The application discloses a trimming device, a control method of the trimming device and a cylindrical battery. The trimming device comprises a fixing mechanism and a
grinding mechanism. The fixing mechanism comprises a first driving member and a fixing
assembly. The first driving member is configured to drive the fixing
assembly to rotate around an axis parallel to a first direction. The
grinding mechanism comprises at least two pulleys, a sand belt, a carrier member, a second driving member and a third driving member. An included angle between a plane of a
grinding section of the sand belt and the first direction towards the fixing mechanism is α, and the following relationship is satisfied: 40°≤α≤50°. The at least two pulleys are rotatably arranged on the carrier member. The second driving member is connected with the carrier member and is configured to drive the carrier member to rotate around an axis parallel to the pulleys. The third driving member is connected with at least one
pulley and is configured to drive the
pulley to rotate. The technical scheme can realize
rounding of a weld at an edge of a workpiece to be processed, and can remove sharp points or protrusions and other adverse phenomena in the weld area at the edge.