Due to the important parameters of Loran-C signal amplitude, secondary phase delay and deformation are closely related to the ground electrical parameters and terrain fluctuations, the Loran-C signal simulator based on complex terrain is designed. The groundwave attenuation factor at different frequencies is calculated using the integral equation method, which multiplied by the standard signal in the frequency domain, and after IDFT, encoding and modulation, an actual signal containing ground electrical parameters, terrain features, and time information are generated. Taking Hexian County ( transmitting station) to Xi’ an ( observation point) as an example, the actual signal amplitude is reduced by 1. 47 dB, the secondary time delay is increased by 0. 407 μs, and the signal is widened by about 1. 5 μs relative to the uniform and smooth path. The experimental results show that the Loran-C signal simulator based on complex terrain can provide a navigation signal closer to the actual transmission path for the development, debugging, testing and maintenance of Loran-C receiving equipment.