Abstract: In order to improve the positioning performance of pseudo-range single-point positioning (SPP) technology in Global Navigation Satellite System (GNSS), a moving horizon estimation (MHE) algorithm with height constraint was proposed. On the basis of adding height as nonlinear constraint to SPP parameter estimation, constrained MHE algorithm is used to improve the accuracy of SPP. Experiments show that compared with the least squares (LS) method, the MHE filter based on high constraint has better smoothing performance, and the effectiveness and feasibility of MHE scheme with additional height constraints are verified. The results obtained are of great significance to the practical application of SPP.