Abstract: The oil film thickness of the distribution pair of the bent-axis pump is tested dynamically in this paper. On the basis of synthetical consideration of the leakage flow rate, the loss of power and the ability to resist contaminant of the distribution pair,the parameters used to describe the distribution state are optimized. According to theoretical analyses and experimental research, the structure of the distribution plate is improved, and the ability to resist contaminant wear of the distribution pair is increased. Thus, it is possible to prolong the service life and working reliability of the pump.