A simulation device for magnetic closing of flap valve is disclosed, which includes a worktable, a driving mechanism for driving the worktable to rotate, a valve seat, a magnetic valve cover movably connected with the valve seat, a first magnet for repelling the magnetic valve cover, a cylinder, a lifting equipment for driving the cylinder to rise and fall. When the cylinder is inserted into the valve seat driven by the lifting equipment, the cylinder prevents the closure of the magnetic valve cover. When the cylinder is out of contact with the magnetic valve cover driven by the lifting equipment, the magnetic valve cover is closed, and the worktable in the simulation device can rotate and turn over, so that the closing process of flap valve (valve seat and valve cover) in any direction of deep drilling coring under the action of magnetic force is simulated.