Method of treating composite piston pin and surface treated composite piston pin

A surface treated composite piston pin, comprising:

• a composite inside layer configured to have a pipe shape and include a reinforcing fiber and a resin;
• a composite outside layer configured to be connected to the composite inside layer along an outside surface of the composite inside layer, have surface roughness Ra equal to or less than 0.42 μm, and include a reinforcing fiber having elasticity higher than that of the reinforcing fiber of the composite inside layer and a resin;
• and
• a coating layer configured to be coated on a surface of the composite outside layer to reduce a friction coefficient.