The utility model relates to the technical field of hydrological monitoring accessory devices, in particular to a water flow and sediment flow detection device. The use limitation is low, the measurement position of the main body can be freely adjusted, the working efficiency is high, the measurement effect is strong, and the practicability is high; moreover, silt in the placement cavity can be cleaned conveniently, large-amplitude deviation of detection data can be reduced, convenience is brought to a user, and therefore the use reliability of the device is improved; the device comprises a main body, a filter plate, a filter screen and a baffle, a containing cavity is formed in the main body, and a water inlet is formed in the top of the main body; the device further comprises a supporting frame, a connecting rod, a contraction frame, a servo motor, a chain, two sets of connecting frames and two sets of connecting ropes, a connecting shaft is arranged between the two sets of connecting frames, and two sets of transmission shafts are arranged at the output ends of the two sets of servo motors correspondingly; a taking and placing opening is formed in the front side wall of the mainbody, two sets of sliding rails are further included, two sets of sliding grooves are formed in the two sets of sliding rails correspondingly, and two sets of sliding plates are arranged at the leftend and the right end of the filtering plate correspondingly.