The invention provides a magnetron sputtering device and a magnetic field distribution adjusting method thereof, and relates to the field of magnetron sputtering. Poor stripes of a planar target material can be effectively improved, and the utilization rate of a target material and the film formation homogeneity can be improved. The magnetron sputtering device comprises a sputtering cavity, the planar target material, at least three sets of electromagnetic coils, a driving unit and connection wires, wherein the planar target material is arranged in the sputtering cavity; the at least three sets of electromagnetic coils are arranged on the part, away from one side being sputtered, of the planar target material, one end of each set of electromagnetic coil faces the planer target material, and the other end is away from the planar target material; the driving unit is configured to control on-off and magnetism direction of each set of electromagnetic coil; and the connection wires correspond to the three sets of electromagnetic coils one by one, and are configured to be electrically connected with the three sets of electromagnetic coils and the driving unit.