The invention relates to a livestock killing machine in an improved structure and belongs to the technical field of killing equipment. The livestock killing machine comprises a trapping tube mechanism, a front push plate, a back push plate, a livestock hip driving mechanism, a strangulation mechanism, a livestock head tuning mechanism, a killed livestock pushing-out mechanism, a cavity door opening and closing device and a motive power transmission mechanism, wherein the trapping tube mechanism comprises a first base, a second base, a first cross beam, a second cross beam, a top plate, a bottom plate, a left rotary disc, a right rotary disc and a livestock collecting groove, the front push plate is arranged on the left rotary disc, the back push plate corresponds to the front push plate, the livestock hip driving mechanism is arranged on the wall body of one side of the front push plate, the strangulation mechanism is arranged in the center position of the first base, the livestock head turning mechanism is arranged on the strangulation mechanism, the killed livestock pushing-out mechanism is arranged on the upper part of one side of the front push plate, the cavity door opening and closing mechanism is arranged on the right rotary disc, the motive power transmission mechanism comprises a motor, a speed reducer, a chain wheel shaft, a first chain and a second chain, and the motor is a positive and reverse rotation motor. The livestock killing machine has the advantages that the structure is simplified, the ideal driving effect on the livestock hip is realized, the strangulation action can be smoothly carried out, the damage to the trapping tube mechanism caused by straggling is avoided, the strangulation force balance is good, and the left rotary disc and the right rotary disc can smoothly rotate.