Fault location of DC distribution network is an important approach to troubleshoot faults and ensure line safety. Based on this, a fault location method of DC distribution network based on the initial value of current differential is proposed in this paper. Firstly, the differential equations of the fault current of the DC distribution network based on the voltage source converter are derived when the bipolar short-circuit fault and the unipolar ground fault occur. Then, the fault types are determined by the difference of voltage and current of positive and negative lines in bipolar short-circuit fault and unipolar ground fault. Secondly, the fault current information is extracted by the discharge process of the DC side capacitor of the voltage source converter, and the differential equivalent expression of the fault current is obtained according to the voltage drop on the current limiting reactor. On this basis, the mathematical model of fault location is obtained by the differential initial value equation of fault current derived simultaneously, so as to achieve fault location. Finally, a simulation model is built using the PSCAD/EMTDC simulation platform to verify the effectiveness of the proposed fault location method.