The invention belongs to the technical field of scrap iron clearing tools, and particularly relates to a mechanical semi-automatic scrap iron collecting device. The mechanical semi-automatic scrap iron collecting device comprises a trolley body, a magnetic recycling mechanism, a discharging mechanism, a discharged scrap containing mechanism, universal wheels and advancing wheels, wherein the trolley body is a frame welding type trolley body; the magnetic recycling mechanism adopts a belt type transmission mechanism and comprises a driving wheel, a strong magnet integrating device, a conveying belt, a steering wheel and a driven wheel; the discharging mechanism adopts crank and rocker mechanisms, and comprises discharging devices, fixed hinges, connecting rods and crank wheels; the discharged scrap containing mechanism adopts a suspension type structure and comprises a reset spring, a positioning block, a push rod, a sliding chute, a supporting plate and a scrap containing box; and the strong magnet integrating device and the discharging device both adopt a frame type sealing structure and each comprise an upper cover plate, a magnetic isolation plate, strong magnets, a frame and a lower cover plate. The mechanical semi-automatic scrap iron collecting device is applicable to occasions such as machining and bench working, simple in operation, safe, reliable, low in energy consumption and free of noise.