本文推导了压力输水管中一维非恒定水流特征线方程的普遍差分形式;为克服声速变化时,特征线弯曲给计算带来的困难,引用Massau积分法;为更灵活地控制计算时距,采用了任起算点浮动的一种等时距方法;给出了一些边界、间断的处理方法.作为例举,将计算结果与Streeter的试验数据进行了比较. In this paper, the general differential form of the one-dimensional unsteady flow characteristic line equation in pressurized water pipe is deduced. To overcome the difficulty of calculation caused by the characteristic curve bending when the velocity of sound changes, Massau integration method is used. In order to control the time span more flexibly, A kind of isochronous method which is used to calculate the float of the point is adopted, and some boundary and discontinuity methods are given. As an example, the calculated results are compared with Streeter’s experimental data.