Abstract: Magnetic tube is widely used in coal, non-ferrous metal, rare metal and nonmetal industries. In order to enable it to be specifically suited to the application in different sectors, it is required to explore the factors affecting the operating efficiency of the tube. The analysis of such factors is made with the focus on the effect of current intensity. Through calculation and analysis of the magnetic force to which particles are subjected in the magnetic separation tube, it is derived that the magnetic force is directly proportional to the product of magnetic induction intensity and its gradient, and the derived result is verified by ANSYS simulation.