The invention discloses a feeding system of solid polyolefin catalysts. The feeding system comprises a catalyst tank and a rotary feeder; a feed outlet of the catalyst tank is connected with the upperpart of the rotary feeder through a first pipeline; the lower part of the rotary feeder is connected with a second pipeline; the first pipeline and the second pipeline are provided with valves; the rotary feeder comprises a housing, a ball body, and a connecting shaft; a cavity is formed in the housing; the surface of the ball body is provided with a circular groove; the ball body is arranged inthe cavity, is pressed against the cavity firmly, and is capable of rolling in the cavity along the transverse direction axis; the connecting shaft is arranged on the transverse direction axis of theball body; the housing is provided with a hole corresponding to the connecting shaft; and the connecting shaft is designed to penetrate the hole. The pipeline on the tank bottom of the catalyst tank of the feeding system is provided with the rotary feeder, and catalyst charging amount can be controlled through adjusting the rotating speed of the rotary feeder, so that continuous, accurate, and stable introduction of solid catalysts into a polymerization reactor can be realized using the feeding system.