The invention belongs to the technical field of machinery, in particular to a controllable discharge safety automatic disassembly device for a waste hard shell lithium ion power battery, Including anexhaust gas filtration tank, an Intake pipe, a check valve, an air cylinder, an Outlet pipe, a suction pipe first pipe, case, a pipe fixing plate, hose, a second pipe, a solenoid valve, a first motor,a slider, a nitrogen tank, a transverse plate, a mounting plate, a funnel, a storage plate, support legs, a waste liquid collection bottle, a filter screen, a support column, a first pressure plate, asecond pressure plate, a case door, a second motor a amounting plate , second motor, a aguide rail mounting pl ate, guide rail, screws, a cutting knife and a screw mounting plate. The disassembly efficiency of the invention is high, As that liquid nitrogen cool the cutting place during the cutting of the power battery, the occurrence of the spontaneous combustion of the battery caused by excessive temperature during the cut is avoided, the battery explosion is avoided, the battery is cut in the box body, the personal safety of the dismantling personnel is facilitated, and the gas filtering mechanism avoids the pollution of the environment caused by the waste gas during the dismantling.