The invention provides a method for testing reflection responses of two impedance discontinuity points on a transmission line. The method comprises the steps of firstly performing time domain transform on a measurement result of the frequency domain, and acquiring time domain responses of the two impedance discontinuity points; then performing gating on the time domain results respectively, and then respectively converting gated data back into the frequency domain; then building an equation in allusion to each gating result in the frequency domain according to the flow direction of signals, wherein each equation contains a reflection coefficient of the corresponding impedance discontinuity point and a transmission coefficient of each segment of the transmission line; finally, solving a simultaneous system of equations to acquire the reflection coefficient of each impedance discontinuity point. Compared with a direct time domain measurement method, the testing method provided by the invention can eliminate influences brought about by mutual reflection of the impedance discontinuity points, the reflection coefficient of the position where reflection occurs is acquired, and the accuracy is obviously improved; and transmission characteristics of the transmission line can be acquired at the same time.