While the global positioning system (GPS) is widely used, it is also susceptible to external interference. Therefore, it is of great significance to study the reliability of GPS navigation receivers. Ultra-wideband (UWB) electromagnetic pulse has a steep rising edge and a wide spectrum, it can interfere with GPS and has become a new navigation interference method. This paper explores the interference mechanism of repeated frequency UWB electromagnetic pulses to GPS navigation receivers by analyzing their energy spectrum line distribution and studies the relationship between their interference effect on GPS receivers and the pulse parameters. The results show that repeated frequency UWB electromagnetic pulses can cause nonlinear interference to the radio frequency front-end circuit of the navigation receiver, reducing the receiver's acquisition performance. Increasing the pulse field strength or repetition frequency can enhance the interference effect and even cause the receiver to lose its acquisition ability.