Abstract: According to transmission line theory and distributed parameter theory, it is pointed out that the sampling waveforms distortion is produced by multi-capacitance loading of fast-pulse transmission line. The equivalent distributed capacitance compensation model is proposed, the two matching computing methods and formulas are given. The results of numerical computation show that pulse transmission line of multi-small-loading capacitance with proportional spacing can be well compensated by the equivalent distributed capacitance method.