The invention belongs to the technical field of painting, and discloses a cylinder outer circle surface painting device which is used on an automatic or self-automatic production line. According to the cylinder outer circle surface painting device, two peristaltic pump tackles with collinear center lines are arranged on a middle cross beam of a machine frame, the two peristaltic pump tackles are guided by linear guide rails and driven by a push cylinder to walk horizontally in a reciprocating mode, each tackle and a guide rail pair of each tackle are both fixed on the upper surface of the middle cross beam of the machine frame through screws, the peristaltic pump tackles sprinkle painting evenly on the surface of an outer circle of material through droppers, a row-type brush is arranged on the middle cross beam of the machine frame, and painting even painting on the surface is achieved through the rotation of a work piece. The cylinder outer circle surface painting device has the advantages of being capable of adjusting painting supply amount randomly and accurately through adjustment for peristaltic pump frequency, guaranteeing product precision requirements, and achieving the automatic production of the cylinder outer circle surface painting on the basis that the painting supply amount can be randomly and accurately adjusted through the adjustment for the peristaltic pump frequency, and the product precision requirements can be guaranteed.