Abstract: This is a paper in the field of mineral processing engineering. Phosphogypsum is a by-product produced during the production of wet process phosphoric acid. At present, China's phosphogypsum has a large annual new emissions, environmental and safety risks, which seriously restrict the sustainable and healthy development of phosphorus chemical enterprises.In order to solve the problem of high silica content in Sichuan phosphogypsum, the desilication tests werecarried by reverse flotation process.The test results showed that through reverse flotation process of "one roughing, one cleaning, one scavenging, middling returning in sequence", gypsum concentrate was obtained with yield of 89.63%, grading 1.85% SiO₂, grading 96.85% calcium sulfate dihydrate with recovery of 96.72%, under conditions of pulp pH valuewith 5.3, BK421B as collector. The research provides technical support for resource utilization of phosphogypsum.