Since the power of satellite navigation signals is very low, satellite navigation signals are susceptible to interference. Currently, satellite navigation anti-interference algorithms mainly use the method of inverting the covariance matrix, such as space, space-time and space-frequency anti-interference algorithms. However, as the number of antenna array elements, the number of space-time taps, and the frequency points of the space-frequency algorithm increase, the matrix dimension also increases, resulting in an increase in the amount of calculations. The conjugate gradient method can avoid the inversion of high-dimensional matrices. It has the characteristics of fast convergence and small amount of calculation. Therefore, the space-time anti-interference algorithm are studied based on the conjugate gradient method, and the effectiveness of the proposed method is proved through simulation analysis.