The performance optimization of narrowband interference is discussed in view of two problems: the randomness of Global Positioning System(GPS) satellite signal and the cost of interference engineering. Firstly, on how to offset the randomness of satellite signals, the interference effects of different interference positions of single-frequency signals and narrow band Linear Frequency Modulation(LFM) signal bandwidth settings on GPS receivers are simulated and analyzed. Secondly, on how to reduce the cost of interference engineering, the method of replacing single interference with multiple interference is used for experimental analysis. The simulation results show that the interference uncertainty caused by the randomness of satellite signals can be eliminated to a certain extent by using the optimal interference position or the uniform and random distribution in the GPS signal bandwidth, and the total cost of interference can be reduced by replacing single signal with multiple signals.