Abstract: In order to improve the construction efficiency of foundation preloading of railway turnout beam supports and adapt to the construction conditions and construction period of the site, an expanded foundation preloading method based on the load applied by a static pressure pile machine was proposed. Relying on the railway turnout beam project on the east coast of Malaysia, fast and slow maintenance load pre-compression schemes were designed. The variation rule of foundation settlement within the load duration was analyzed through FEM simulation, and the reasonableness of the proposed construction scheme was verified with on-site tests. The results are as follows. The settlement trend after the repressurization of the expanded foundation changes from steep to slow. Compared with the pile load method, the preloading completion time required for both preloading schemes is significantly reduced. Under the same preloading load conditions, the foundation settlement is gradually stabilized after maintaining the maximum load for 1 h, that is, the extending the load maintenance time has limited influence on the foundation preloading effect. The settlement change at both ends of the expanded foundation is not the same during the construction process, but it tends to be consistent with the completion of preloading, and the flatness meets the construction requirements. The measured cumulative settlement of the expanded foundation under fast maintenance load pre-compression does not exceed 0.15 mm, which not only can effectively shorten the construction period, but also has a better pre-compression effect than the slow maintenance load pre-compression program.