A fault location method based on double-ended travelling wave principle is presented for the 110 kV and above high-voltage overhead lines combined with underground power cables. Firstly， the fault section is determined by comparing the time difference between the arrival times of the fault induced initial travelling wave detected at two ends of the combined line with a setting value. Then， according to the different fault section， the corresponding fault location algorithms for combined lines based on double-ended travelling wave principle are derived. In order to test the validity of the presented travelling wave based fault location method for combined lines， the fault location algorithms are embedded into the ordinary double-ended travelling wave based fault locators， and a simulation test for the changed fault locators are completed using the special verification instrument for travelling wave based fault locators. The test results show that the presented fault location method for combined lines based on travelling waves is feasible and practical.