1. A water flow control valve comprising a valve shell, a sliding block, an movable valve piece, a fixed valve piece, a valve base and a check valve;wherein the sliding block, the movable valve piece and the fixed valve piece are stacked from top to bottom and are positioned inside the valve shell; the sliding block has a valve rod which is formed at an upper portion thereof and sticking out of the valve shell, and a bottom portion of the sliding block is engaged with the movable valve piece such that, through operating the valve rod, the sliding block is configured to drive and have movements with the movable valve piece concurrently to perform different aligning patterns between the movable valve piece and the fixed valve piece, thereby enabling the water control valve to control on/off operation of a faucet, the amount of water flow and the mixing ratio of hot/cold water; the valve base is configured to block a bottom portion of the valve shell, thereby preventing the sliding block, the movable valve piece and the fixed valve piece from falling out of the valve shell; the valve base comprises a water inlet chamber, and the check valve is installed therein;
wherein the valve shell comprises a housing chamber formed therein, and an upper opening is formed at the upper end of the valve shell; the sliding block, the movable valve piece and the fixed valve piece are configured to be positioned inside the housing chamber of the valve shell in sequence, and the valve rod is configured to stick out of the valve shell through the upper opening; the housing chamber comprises at least a water outlet opening penetrating through a lateral wall of the valve shell;
wherein the movable valve piece has a mixing hole vertically penetrating through a central portion thereof, and a top surface of the movable valve piece has at least a horizontal water channel which is communicated with the mixing hole;
wherein the fixed valve piece has a first water inlet hole and a second water inlet hole, which are formed at corresponding positions and respectively penetrate through a bottom portion of the fixed valve piece; a first water outlet hole vertically penetrating through the fixed valve piece is located between the first water inlet hole and the second water inlet hole;
wherein the valve base comprises the water inlet chamber and a water outlet chamber, which are separately formed at an interior space of the valve base; a cold water inlet hole and a hot water inlet hole respectively penetrate through a top portion of the valve base to communicate with the water inlet chamber, and a second water outlet hole penetrates through the top portion of the valve base to communicate with the water outlet chamber; the movable valve piece and the fixed valve piece are overlapped and positioned inside the housing chamber, and the valve base is configured to support and engage with the fixed valve piece; the cold water inlet hole, the hot water inlet hole and the second water outlet hole are configured to be respectively aligned with the first water inlet hole, the second water inlet hole and the first water outlet hole; before the valve rod is operated, the mixing hole of the movable valve piece is positioned at a position misaligned with the first water inlet hole and the second water inlet hole of the fixed valve piece such that both of cold water and hot water are configured to be blocked by the movable valve piece and the faucet is closed; and
wherein the check valve has two symmetric housing members which are configured to fit together to secure a fixed tube, a movable valve core and two springs therein; each of the housing members has a passage, a water inlet end and a water outlet end, which are communicated with each other; the two passages are configured to communicate with each other to form an accommodating space for the fixed tube, the valve core and the two springs; the check valve is configured to be positioned inside the water inlet chamber of the valve base, and the two water outlet ends of the two housing members are respectively aligned and communicated with the cold water inlet hole and the hot water inlet hole; the fixed tube has at least a sealing ring disposed on an outer periphery thereof, and two first openings formed at the outer periphery of the fixed tube are respectively located close to two ends of the fixed tube; two axial compartments respectively formed at two ends of the valve core are separated by a partition, and each of the compartments has a second opening formed at an outer periphery thereof; when cold water and hot water flow into the check valve, the valve core is configured to have movement relative to the fixed tube to change a relative position between the first opening and the second opening such that the check valve is configured to balance the water pressure difference generated from the cold water and hot water; the two springs are respectively positioned inside the two compartments of the valve core, and each spring has a first end and a second end respectively; said first end abutting against a sidewall of the housing member and said second end abutting against the partition; and the valve core abutted by the springs is configured to keep at a central position of the accommodating space before water flows into the check valve.