Abstract: This is an essay in the field of mineral processing engineering. In order to make more efficient use of the resources in cassiterite tailings, we put forward the process flow of combined operation of flotation column and flotation machine on the basis of traditional flotation process. Among them, the flotation column for roughing and scavenging operations can give full play to the advantages of large processing capacity and high enrichment ratio of the flotation column; the selection operation of flotation machine can improve the overall stability of the process. Through this experiment, it is shown that under the premise of feeding ore grade of 0.28%, cassiterite middlings with grade of 15.26% and recovery rate of 61.13% can be obtained by combined flotation of flotation column and flotation machine. After shaking table operation, the concentrate grade reaches 40.87%, which can reach the index of grade 6 tin concentrate. The test results show that this process has good adaptability to low-grade and fine-grained cassiterite ore, and can reduce the construction land of the concentrator, which has certain promotion significance.