1. An insertable fixing module of an industrial cabinet rail, wherein the industrial cabinet has a frame installed at four corners of the industrial cabinet separately, and the frame has a plurality of latching holes arranged with an interval apart from one another, and the fixing module is installed at an end of a rail facing an outer side of the industrial cabinet, and the fixing module is installed horizontally between the frames, and the insertable fixing module comprises:a main body, fixed to a front end portion of the rail, and having a pair of positioning bumps configured to be corresponsive to the latching holes respectively and arranged with an interval apart from each other, an accommodating space formed inside the main body, and a chute extended from one of the positioning bumps in an axial direction, so that the chute and the accommodating space are communicated with each other;
a hook, movably installed in the chute, and having at least one inverted hook portion disposed at an end of the hook and configured to be corresponsive to the latching hole, and the other end of the hook being extended into the accommodating space to form a junction;
a linking slider, movably installed in the accommodating space, and having a combination slot configured to be corresponsive to the hook and disposed at a front end of the linking slider, and the junction of the hook being installed into the combination slot, a spring installed to a top side of the linking slider for abutting a side of the accommodating space and abutting the linking slider to expose the inverted hook portion of the hook from the positioning bump, and the linking slider having a linking slope, and a direction of the linking slope being corresponsive to a contraction direction of the spring; and
a press key, movably installed in the accommodating space, and having a driving slope configured to be corresponsive to the linking slope, so that the press key is disposed on a side of the linking slider, and a direction of the driving slope being configured to be corresponsive to the moving direction of the linking slider, and the moving direction of the press key being configured to be corresponsive to the extending direction of the rail; thereby, during installation, the pair of positioning bumps are inserted into the two latching holes respectively, and the hook is provided and popped out to define a latched status of fixing the frame; and after the press key is pushed inwardly along the extending direction of the rail, the hook is withdrawn into the positioning bump to define a released status.