The invention discloses an automatic etching apparatus for a PCB (printed circuit board). The automatic etching apparatus comprises a base, a reaction tank, a cover plate, stirring motors, rotating shafts, impellers, stand columns, a cross beam, a walking assembly, an air cylinder, a suspension plate, a storage assembly, a heating assembly, a first working table, a controller, a second working table, a material tank and a membrane pump, wherein when the automatic etching apparatus is in use, the storage module fully loaded with the PCBs are manually suspended below the suspension plate; the controller controls a servo motor to drive a sliding base fixedly connected with a feed nut to move leftwards through a guide screw; after the servo motor moves to a set position, the air cylinder pushes the storage assembly to move downwards to be immersed in the reaction tank that is full of reaction liquid; and then the stirring motors drive the impellers to turn through the rotating shafts to enable the liquid in the reaction tank to flow in real time for performing etching for the PCB. The automatic etching apparatus is simple in structure, and capable of automatically etching the PCB through manual feeding; the reaction conditions are monitored and controlled in real time, so that uniform etching for the PCB is achieved; and meanwhile, the labor intensity of operators is lowered, and the production efficiency is improved.