The invention discloses a composite machining process and machining method of a roller hard-surface. The method comprises the following steps of: (1) performing heat insulation and preheating treatments on a roller; (2) continuously overlaying the external surface of the roller which is subjected to heat insulation and preheating treatments, and compositely machining the overlaid material still in a hot melting state in the later stage of the overlaying to prepare a roller surface, wherein the composite machining comprises surface overlaying and the cutting of the overlaid materials; (3) performing thermal process after welding for the roller surface, and removing the welding stress; (4) cooling the roller to the room temperature after the roller is subjected to through postweld heat treatment, performing flaw detection on the roller hard-surface; (5) performing grinding machining on the roller surface to prepare the required roller hard-surface; (6) performing product inspection on the roller hard-surface, and detecting the size and the hardness. Compared with the prior production manufacture process and production method, the composite machining process disclosed by the invention has the advantages of relatively low production manufacture cost and relatively short production manufacture period.