1. A method for dyeing a knitted fabric, comprising:providing an undyed knitted fabric;
spray dyeing the undyed knitted fabric by a dye liquor containing nano-particles through a printing and spraying process, the dye liquor containing nano-particles including dye nanoparticles, dispersants, auxiliaries, or their combinations thereof;
executing a high temperature process or a steam process of a thermal process to the spray dyed knitted fabric such that the nano-particles attach into fibers of the spray dyed knitted fabric; and
forming a knitted fabric with a predetermined color after dyeing.