The invention discloses a spraying device for uniformly spraying the inner wall of a pipeline. The spraying device comprises a base and a coating pipe, wherein a connecting shaft is arranged in the base, the two ends of the connecting shaft are connected with first rollers in a rotating mode, a first gear is rotationally connected to the connecting shaft at the rear side, a protective shell is arranged on the surface of the base, a motor is arranged in the protective shell, the motor is rotationally connected with a motor shaft, the motor shaft is rotationally connected with a second gear, thesecond gear is connected with a first gear in a meshed mode, shock absorbers are arranged on the periphery of the protective shell, and the tops of the shock absorbers are connected with the bottom of the shell. The spraying device for uniformly spraying the inner wall of the pipeline is provided with the base, the first rollers, the motor, telescopic connecting rods, telescopic supports, springs, second rollers, a spraying disc and a nozzle, so that the self-walking capability is provided for the device, the stability of the device in moving in the pipeline is improved, uniform spraying of the interior of the pipeline is ensured, and the using convenience is improved.