在概率分布线型确定下,水文频率计算就是根据样本资料估算其中包含的参数。计算P-Ⅲ型分布参数的方法很多,目前常采用的最简单的方法是三点法,用图解适线求参数。本文中笔者建议用二点法直接利用K值表求参数。该方法简便,且不易出错。同时又能保证适线法的精度要求。 Under the linear distribution of probability distribution, hydrological frequency calculation is based on sample data to estimate the parameters contained in it. There are many ways to calculate P-Ⅲ distribution parameters. At present, the simplest method commonly used is the three-point method. In this paper, I suggest using two-point method to directly use the K value table to find the parameters. The method is simple and not easy to make mistakes. At the same time, it can guarantee the accuracy requirement of the line method.