Cam-shaft is a machinery which controls combustion engine. Cam-shaft in combustion engine of moto-bike has innet cam and exhaust cam. This cam-shaft works in sliding friction condition and oil lubricated. In order to enhance lifetime of camshaft, surface of camshaft need to be well polishing. In this paper, the author promote a design of motobike cam-shaft polishing machine in order to increase productivity of manufacturing process. This machine is automatic controlled by PLC. To design a camshaft polishing machine, technical characteristics of camshaft then decided camshaft polishing method, camshaft mounting method then design kinetic diagram of camshaft polishing machine and design camshaft polishing machine. The design of camshaft polishing machine has been verified by a real camshaft polishing machine, this machine satified all requirements from industrial companies and it is able to replace the imported machines.