The invention designs a downwind pitch-controlled wind-driven generator, which mainly comprises a hub, a main shaft, a generator, a chassis and a base, a synchronizing disk is arranged in the hub, and is connected with a blade-connecting rotating bearing through two butted knuckle bearings, one end of a reciprocating rod arranged in the main shaft is connected with the synchronizing disk, the other end of the reciprocating rod is connected with a shifting sleeve, and an electric push rod is arranged in the chassis, and is connected with the shifting sleeve. The downwind pitch-controlled wind-driven generator is mainly applied to medium and small-sized fans, a pitch-controlling mechanism of the downwind pitch-controlled wind-driven generator can simultaneously control three blades to change pitches, and can keep the amplitudes of pitches in consistency, and under harsh conditions such as a hurricane, the pitch-controlling mechanism can control the pitches of the blades to a certain negative angle, so that the downwind pitch-controlled wind-driven generator can be shut down and kept in the shutdown state. The chassis can be rotated relative to the base by 360 degrees in order to be adapted to each wind direction. In addition, the downwind pitch-controlled wind-driven generator is also provided with an anemoscope and a controller, and consequently, the reaction is more sensitive, so that the downwind pitch-controlled wind-driven generator can be adapted to suddenly changed wind direction and wind speed.