To address the problem of insufficient precision of existing single-satellite positioning techniques, a direct positioning method of interference source for satellite navigation system based on propagation operator is proposed. Firstly, the received signal of the satellite is modeled and the covariance matrix at each moment is calculated. After blocking the covariance matrix, the propagation operator is obtained to estimate the orthogonal projection subspace of the steering vector. Then the loss function can be established and the position of the interference source can be estimated by searching the loss function. Theoretical analysis and simulation results prove that the localization accuracy of the proposed method is comparable to that of the traditional Multiple Signal Classification(MUSIC) -based direct positioning algorithm, while the calculation complexity is greatly reduced. Meanwhile, the localization accuracy is much higher than that of the existing bearing-only localization techniques, which is valuable for practical engineering applications.