A large number of surface structures along active faults are damaged during earthquakes.Accurate estimation of the surface displacement induced by fault dislocation is critical as it accounts for the damage to surface structures. A valid asperity dislocation model helps calculate surface displacement more accurately. To examine how asperity heterogeneity affects surface displacement, this paper proposed an improved asperity dislocation model that considers the non-uniformity of asperity dislocation based on traditional asperity dislocation models. To validate the proposed asperity dislocation model, we chose the 1989 Loma Prieta earthquake as a target event. Surface displacements that induced the Loma Prieta earthquake under different asperity models were calculated. Results were compared with actual surface displacement measurements obtained by inversion. An area of 43 km ²calculated by the proposed non-uniform asperity model demonstrates a difference in surface displacement exceeding 8 cm compared with actual results, which is reduced by 25 %compared with the results derived from the uniform asperity dislocation model. The area with a difference in the horizontal surface displacement exceeding 8 cm is 117 km, which is reduced by 31 %compared with the results derived from the uniform asperity dislocation model. Furthermore, this paper applied the proposed non-uniform asperity dislocation model to calculate the surface displacement induced by the 1679 Sanhe-Pinggu M8.0 earthquake. Areas with surface displacements greater than 1 m and 2 m were summarized, and the maximum horizontal and vertical surface displacements were calculated. Outside Beijing, the maximum vertical and horizontal surface displacements occur near Sanhe City and exceed 4.8 m and 2.6 m, respectively. In Beijing, the maximum vertical and horizontal surface displacements appear in Tongzhou and the Pinggu District, which exceed 1 m and 2.6 m, respectively. The research results provide a reference for future seismic fortification in Beijing.