The invention discloses a power cable main insulating layer stripping device which comprises a base (1), a tool locating seat (2) and a cable locating seat (4). The tool locating seat (2) and the cable locating seat (4) are both arranged on the base (1), the tool locating seat (2) is connected with a blade (3) and a limiting baffle (5), an edge of the blade (3) is upward, and a locating gap is formed in the side, exactly facing the blade (3), of the cable locating seat (4). Through the structure, the overall structure is simple, implementation is convenient, cost is low, operation is convenient and fast when the stripping device is used for stripping a power cable main insulating layer, and a cable inner core can be prevented from being damaged.