Abstract: The magnetic field distribution of magnetron sputtering coating equipment has a serious effect on film coating. In order to improve the utilization ratio of target of magnetron sputtering source, we abandoned the traditional ring forms of magnetic field runway design concept, and put permanent magnets or electromagnet separation sputtering on both sides of the target, which generated magnetic constraints (magnetic mirror) field on the target surface. This design used finite element analysis method for magnetic field simulation calculation, and the reliability of the finite element method was verified by simulation results and measured results of magnetic field. Ansys finite element analysis software was used for magnetic field distribution simulation, calculation was simplified and design cycle was reduced. Experiment indicates that the constraint magnetic field can greatly improve the utilization ratio of target.