The invention discloses a rainwater collecting and retreating device. The device comprises a rainwater collecting device, a settling device, a connecting device, a first filtering device, a motor device, a second filtering device and a discharge device, wherein the rainwater collecting device comprises a rainwater collecting frame, first supporting rods, a first pipeline and a first valve, the settling device comprises a first frame body, a first filter screen, first springs, a first support, a first sponge block and a second spring, the connecting device comprises a second pipeline, a second valve, a second support, a third support and a first slant rod, the first filtering device comprises a second frame body, a sealing ring, a second filter screen, a second support rod, a third support rod and a third pipeline, the motor device comprises a motor, a rotating shaft, first stirring rods, second stirring rods, first bristles, a locating shaft, a fourth support, a first cross bar and a fifth support, and the second filtering device comprises a third frame body, a roller, second bristles, a sixth support, a fourth pipeline and a third valve. The rainwater collecting and retreating device disclosed by the invention can effectively collect rainwater, and precipitates and filters rainwater.