A lever type mechanical downward pushing device of a mechanical press comprises a sliding block mounted on a machine body. Supports are mounted on the two sides of the sliding block correspondingly to be connected with vertical upper pull rods. The upper pull rods are connected with lower pull rods through adjusting nuts. The lower ends of the lower pull rods are fixedly connected with pull rod connectors. The pull rod connectors are rotatably and slidably connected with the outer ends of horizontally-arranged levers. The middles of the levers are rotatably connected with fulcrum seats arranged on the machine body. The other ends of the levers are in rolling connection with the lower bottom faces of a pushing seat. The upper end of the pushing seat is vertically and movably arranged in the machine body. A through hole is formed in the center of the pushing seat. An air cylinder is arranged at the bottom of the pushing seat. A piston rod of the air cylinder is mounted in the through hole. The upper end of the pushing seat is in matched connection with the lower end of an upper pushing rod. The upper end of the upper pushing rod is in matched connection with a worktable. The lever type mechanical downward pushing device has the advantages that synchronization is good, symmetrical balance is achieved, ejecting force is large, structure is simple, compactness is achieved, mechanical efficiency is high, manufacturing cost is low, maintenance is easy, environmental friendliness and energy saving are achieved.