The invention provides a process and a system for recovering Zn by cooperatively treating zinc-containing waste oil paint slag and distiller's grains. The process comprises the following steps: firstly, distributing the zinc-containing waste oil paint slag and the distiller's grains in a rotating packed bed pyrolysis device and pyrolyzing to obtain pyrolysis oil gas and zinc-containing pyrolysis carbon; secondly, introducing the zinc-containing pyrolysis carbon into a gasifier for gasifying to obtain a zinc-containing gasified gas mixture; and thirdly, recovering the zinc-containing gasified gas mixture by a dedusting device to obtain gasified gas, metallic zin and pyrolytic ash solid. The process for recovering the Zn by cooperatively treating the zinc-containing waste oil paint slag and the distiller's grains has the advantages that the difficult problem of resourceful treatment of a large amount of the distiller's grains is difficult to realize can be effectively solved; moreover, a new way is found out for treating hazardous wastes such as the zinc-containing waste oil paint slag; the zinc-containing hazardous wastes are adopted as a catalyst, so that effective treatment of the hazardous wastes is realized and a metallic zinc elementary substance is obtained in a simple and feasible way; resource utilization of the metallic zinc and organic matters is realized; and besides, the recovery of the metallic zinc is realized and overall economy of the system is remarkable.