The invention provides a cutting device of a sheet metal part for a power transmitter shell, belongs to the technical field of sheet metal machining, and solves such technical problems as low cutting efficiency and inconvenience for conveying in a traditional cutting device. The cutting device comprises a worktable; and the worktable is box-shaped. The cutting device is characterized in that the worktable includes an upper plate, a lower plate and a side plate; and a conveying mechanism for longitudinally conveying the sheet metal part to the other end of the worktable along the upper plate is arranged at one end of the upper plate. The cutting device has such advantages as high machining automation degree and high cutting efficiency.