In order to reduce the bias drift of the fiber optic gyroscope due to the temperature effect and improve the accuracy, the temperature compensation model of the fiber optic gyroscope was established based on the RBF neural network model based on particle swarm optimization (PSO-RBF), and the temperature compensation test was carried out on the three-axis fiber gyroscope in the temperature environment of -40~+60°C. The experimental results show that the model reduces the bias drift of the whole process of the fiber optic gyroscope by more than 85% under the condition of variable temperature, and its prediction stability and compensation effect are better than the traditional polynomial model and the unoptimized RBF model.