Fault location plays an important role in long distance HVDC transmission system. To solve the problems of inaccurate attenuation coefficient calculation and difficult capture of secondary wave head, a fault location model based on improved Pelican optimization algorithm (IPOA) and optimized least squares support vector Machine (LSSVM) is proposed. Firstly, according to the attenuation principle of traveling wave, the formula of fault distance and modulus maximum ratio of two terminal mode components of the line is derived, and the nonlinear relationship between them is found. Secondly, using LSSVM to generalize the relationship between the two, the improved POA algorithm is used to optimize the key parameters of LSSVM, and the IPOA-LSSVM fault location model is established. By collecting fault signals at both ends, the amplitude ratio of the first wave head is obtained as the input of the model, and the fault distance is used as the output for simulation verification. The simulation results show that the model is not affected by the transition resistance and fault type, and can locate reliably and accurately.