Polymer solar cells with device structure of ITO/PEDOT:PSS/ P3HT:PCBM/Al were fabricated by magnetic field disposal with three different processes. Comparing to the device without magnetic disposal, the short-circuit current density of cell A increased from 1.337 mA/ cm2 to 2.180 mA/ cm2, while the open-circuit voltage of it decreased. In addition, both fill factor and energy conversion efficiency of cell A increased. Differently, the cell B showed little improved properties. This phenomenon could be related to the characteristic of the polymer material, and the mechanism of it is discussed in this paper.