The invention relates to an engine timing chain and a machining method. The surface roughness of pin shafts of the engine timing chain is 0.5 or below, and the surface hardness of the pin shafts is 2000 HV or above. After the chain is subjected to abrasion tests with inferior engine oil on a test bed for 40 hours, the abrasion elongation ratio is smaller than or equal to 0.25%, and the abrasion elongation ratio of the chain is better than that of the international advanced level.