The invention discloses an auxiliary roller, comprising a roller body and a driving device of the roller body. the driving device comprises a base and a rotating driving part arranged on the base and in the roller body; the lower end of the roller body is connected with the base; the roller body serves as both a working device and a shell of the rotating driving part in the roller body; and the rotating driving part drives the roller body to rotate and work. Because the roller body serves as both the working device and the shell of the driving device in the roller body and integrates the working part and the driving part, the structure of the roller body is greatly simplified, the number of parts for realizing the work of the roller body is reduced, and the optimal design of the auxiliaryroller is realized.