The invention discloses a three-phase asynchronous motor end cover hole punching device, which comprises a base, a telescopic cavity, a telescopic column, a fixed seat and a motor. Rotation of a tiller is operated manually, mutual clamping between a gear and a tooth is combined, a bit is thus controlled to move downwardly, and hole punching operation is then carried out on the end cover in a groove; when the end cover is not in the middle or not firmly fixed, the manual operation of rotating the tiller is not required, after the end cover is adjusted to a proper position or is firmly fixed, the bit is then controlled to move downwardly, the tiller is rotated slowly, the hole punching speed can be controlled, and the hole punching finished product is thus improved; the bottom part of the telescopic cavity is provided with a rotating seat, when the end cover needs to be placed, a front-end support can be pushed towards the right, the bit, the motor and the like can rotate for 90 DEG towards the right with the telescopic cavity as a circle center, placing of the end cover can be prevented from being blocked, the front-end support is rotated back after placing, hole punching can be carried out on the end cover, and the hole punching operation process is better facilitated.