The invention provides a process and a system for recovering zinc via synergistic treatment with zinc-containing waste paint slag and distillers' grains. The process comprises the following steps: performing material distribution and pyrolysis on the zinc-containing waste paint slag and the distillers' grains in a revolving bed pyrolysis device to obtain pyrolytic oil gas and zinc-containing pyrolytic carbon; introducing the zinc-containing pyrolytic carbon into a direct combustion boiler for combustion to obtain zinc-containing smoke dust; collecting the zinc-containing smoke dust with a dust collector to obtain zinc oxide and pyrolysis ash. The process for recovering zinc via synergistic treatment with the zinc-containing waste paint slag and the distillers' grains effectively solves the problem that a large quantity of distillers' grains are difficult to be treated resourcefully, and also finds a new way for treatment of hazardous wastes such as the zinc-containing waste paint slag at the same time; by adopting zinc-containing hazardous wastes as a catalyst, effective treatment of the hazardous wastes can be achieved, the problem that the distillers' grains and paint slag are difficult to treat is solved, and the defects of low caloric value of pyrolytic gas when the distillers' grains are pyrolyzed separately and a long pyrolysis time when the paint slag is pyrolyzed separately are solved; moreover, the recovery of metal zinc is achieved, and the overall economical efficiency of the system is significant.