There is a problem of the limits of existing time-domain distance protection when it comes to a grounding fault with high fault resistance occurring at the end of distance section I in a wind power system long transmission line. This paper presents a time-domain distance protection algorithm for a wind power system long line based on the distributed parameter model and the remote end system parameters. The performance of existing time-domain distance protection under the influences of a long line and remote-end system are discussed. Taking into account the distributed parameter effect of the long line, the near-end electrical quantity is calculated to the compensation point at the end of section I on the long line. The time-domain fault loop equation considering the parameters of the remote end system is constructed between the compensation point and the fault branch, and the fault location is obtained by calculating equations. Combined with the protection setting value, the distance protection criterion is realized. Simulation results show that the proposed protection principle considers the influence of a long line distribution parameters and is suitable for long transmission lines. In addition, when a grounding fault with 300 Ω fault impedance occurs at the end of section I for a long line, the protection can still operate correctly by considering the impact on the end system and is less affected by interference factors such as sampling rate. This work is supported by the Science and Technology Project of State Grid Corporation of China (No. 5100-202040327A-0-0-00).