The invention relates to the technical field of painting workshop waste water treatment accessory devices, in particular to a coating process waste water treatment device. In the using process of a sediment scraper, a transmission chain can be subjected to tensioning adjustment, sediment scraping work of the sediment scraper is prevented from being affected, and the use reliability is improved. Meanwhile, an added coagulant and waste water can be subjected to a full mixed reaction, the waste water is completely flocculated, and the use limitation is reduced. Synthetic organic matter, cyclic organic matter, aromatic organic matter and the like in the water left after sediment scraping can be effectively removed, pollution caused to the environment by direct discharge is avoided, and the practicality is improved. The device comprises a box body, a bottom plate, four sets of landing legs, an aerator, the sediment scraper and a drive motor, and a work cavity is formed in the box body. Thedevice comprises a containing plate, a supporting plate, four sets of inserting columns, four sets of inserting pipes, a threaded pipe, a threaded rod, a fastening nut, a front fulcrum rod, a rear fulcrum rod, a supporting shaft and a chain wheel. The device further comprises four sets of auxiliary shafts, a sealing box, a flocculating motor and a driving gear.