The invention relates to square or flat material production line jet cooling thermal treatment equipment, which mainly consists of upper and lower strong cold jet devices (15 and 15a), upper and lower medium cold jet devices (13 and 13a), upper and lower weak cold jet devices (12 and 12a), upper and lower aerosol jet devices (3 and 3a), side cold jet devices (16), front, middle and rear blowing devices (11, 14 and 6), a flow control device (2) and an upper jet device lifting device (1), wherein the upper strong, medium and weak jet devices (15, 13 and 12), the upper aerosol jet devices (3) and the front, middle and rear blowing devices (11, 14 and 6) can lift up and down together with the lifting device (1) so as to adapt to the requirements of square or flat materials of different thicknesses. The side cold jet devices (16) are arranged on two sides of a rail (8), and can quickly cool the thick square or flat materials. The cooling capacity of the cooling system can be regulated by opening the jet cooling devices of different groups and regulating the flow control device (2). Front and rear staggered nozzles dense in the middle and sparse on two sides are arranged so that the jet cooling system is uniform and the quenched square or flat materials have low deformation, unique texture and no cracking.