Accurate fault location of grounding pole in UHVDC project is helpful to improve the efficiency of fault detection, and has important practical significance to ensure the normal operation of grounding pole and HVDC transmission system. In this paper, a fault location method for grounding pole line of UHVDC transmission project based on regression analysis is proposed. Firstly, the variation characteristics of electrical quantity of grounding pole line with different types of faults are analyzed, and the causes of transient overvoltage are studied. Based on the DC value of steady-state voltage and current after fault, and the solution method of transition resistance is given. The relationship model between fault location and transient overvoltage under different transition resistance is established by regression analysis method, and the fault location under different transition resistance is realized. The simulation results of a ±800 kV grounding electrode system show that the proposed method has high faultlocation accuracy and good applicability for different fault transition resistors.