The invention provides a process of recovering and treating the paper mill coating pigment and the secondary use as the coating pigment. The process comprises flocculating, inclined lamellar precipitation, oxidation and viscosity reduction, turbine centrifugation and vertical foundry mill. The treatment object is the paper mill coating wastewater. The step of the process is simple, and the process can not generate the secondary pollution. The quality of the products passes the coating tests and the paper reaches the related standards of the enterprise. The process is a novel technology with environmental benefit, economic benefit and social benefit.