The invention discloses a special-shaped inner and outer cover assembly device comprising a face plate with an annular groove, an outer cover clamps, an inner cover clamp, a thrust cylinder group composed of multiple thrust cylinders, a slider group composed of multiple sliders, an outer cover rotating and positioning mechanism, an inner cover rotating and positioning mechanism, an inner and outer cover sucking mechanism and an inner and outer cover press-fitting mechanism. The sliders are all arranged in the annular groove. The outer cover clamp and the inner cover clamp arrayed in an aligned manner are arranged on each slider. One thrust cylinder is arranged at the edge position of each corner of the face plate and just corresponds to one slider of the slider group. The outer cover rotating and positioning mechanism is located over the outer cover clamp; the inner cover rotating and positioning mechanism is located over the inner cover clamp; the inner and outer cover sucking mechanism is located at the position of a next station after inner and outer covers are rotated and positioned. The technical problem about how to position and assemble the special-shaped inner and outer covers simultaneously can be solved.