The invention provides an automatic shelling device of mytilus coruscus. The automatic shelling device comprises a feeding hole, a controller, a machine base, a first motor, a first linear motor, a first movable block, a first fisheye bearing, a first expansion plate, a supporting plate, a channel, an electrically operated valve, a second fisheye bearing, a first drainage valve, a first water outlet pipe, a second expansion plate, a baffle plate, a rotary shaft, a flange bearing, a mesh plate, a first case, a water inlet valve, a water inlet pipe, a rack, a second motor, a second gear, a second case, a vibrating plate, a third fisheye bearing, a shock insulation plate, a vibrating motor, a second drainage valve, a second water outlet pipe, a chain, a wheel stand, a first gear, a first double-head air cylinder, a second linear motor, a second movable block, a third double-head air cylinder, a second high-pressure nozzle, a third high-pressure nozzle, a second double-head air cylinder, a first high-pressure nozzle, a through hole, a case door, a frame and supporting legs, wherein the first case is mounted below the rack; the feeding hole is mounted on the first case; the water inlet pipe is mounted on the first case. The automatic shelling device has the advantage that the positions of the nozzles can be adjusted.