Abstract:[Objective] Beijing-Tianjin sand control projects have been implemented for 20 years. This study intend to provide further guidance for the implementation of the second phase of the project by evaluating the effects of wind and sand fixation under the influence of the project implementation.[Methods] The vegetation coverage and wind erosion, retention rate of wind, and sand fixation service function were calculated by using a revised wind erosion equation model.[Results] The Beijing-Tianjin aeolian sand source area was dominated by grasslands, followed by forest and farmland. Since the implementation of the project, the average annual amount of soil wind erosion has been 7.87×108 tons, mainly with mired and mild erosion. The amount of soil wind erosion during the implementation of the first phase of the project generally decreased year by year. Since the implementation of the second phase of the project, wind erosion hazards gradually increased, especially in subregions of desertified grasslands, where the change trend of the wind erosion modulus reached 8.96 t/(hm2·a). The average retention rate of the wind and sand fixation service function of the entire sandstorm source area reached 0.82, and the low-value areas were mainly distributed in the desertified grassland subregion (0.743) and the hilly and mountainous area of Northern Shanxi Province (0.752). Since the implementation of the second phase of the project, the retention rate in most areas increased significantly, which was consistent with the changes in vegetation coverage throughout the year as well as in winter and spring.[Conclusion] The focus of wind erosion prevention and control is on areas with a decrease in the retention rate and the desertified grassland subregions, Hunshandake sandy subregion, and Horqin sandy subregion.