By comparing the catalytic activity of two morphology FeS2 particles and its performance in dye-sensitized solar cells(DSSCs), FeS2 particles with higher performance are selected. Cubic and spherical high purity FeS2 are synthesized by hydrothermal method and hot-injection method. Counter electrodes (CEs) are prepared with FeS2 and assembled on DSSCs. By measuring the photoelectric conversion efficiency of battery and catalytic characteristics of CEs, it is found that the spherical particles show higher catalytic activity, and the battery based on spherical FeS2 CEs presents a higher photoelectric conversion efficiency. Under simulated solar light irradiation with intensity of 100 mW/cm2 (AM 1.5), the DSSCs based on the cubic and spherical high purity FeS2 CEs achieve photoelectric conversion efficiency of 4.55% and 5.69%, respectively.