The invention relates to a positive-negative pressure laboratory water quality analysis sample multistage filtering device, and mainly solves the problems of the existing device that the filtration speed is low and the suction filtration effect is poor. The multistage filtering device is characterized in that an upper reducing filter cartridge (3) and a lower reducing filter cartridge (6) are respectively provided with an upper filter cartridge and a lower filter cartridge; a connecting position of the upper filter cartridge and the lower filter cartridge is provided with a ring A (26); a ring A (22) at the bottom of a cylindrical filter cartridge is mounted on the ring A (26), and a filter membrane A is pressed between the ring A (22) at the bottom of the cylindrical filter cartridge and the ring A (26); a filter membrane compression ring A and a filter membrane B are pressed between a ring B (28) at the bottom of the upper reducing filter cartridge and the ring A (26); a ring B at the bottom of the lower reducing filter cartridge is mounted on a ring B at the bottom of a cylinder part at the upper end of a funnel body (14), and a filter membrane compression ring B and a filter membrane C are pressed between the ring B (28) at the bottom of the upper reducing filter cartridge and a ring B (30). The positive-negative pressure laboratory water quality analysis sample multistage filtering device is high in filtration speed and good in suction filtration effect.