In the crossing projects of subway deep foundation pits and large-diameter sewage pipelines, it is crucial to develop an efficient and reliable construction technique to address the structural risks and water seepage issues associated with traditional methods. Based on a rail transit engineering case, this paper proposes an integrated plugging and retaining construction technology. The construction procedures and key parameters of this technology are elaborated, with a focus on the comparative analysis of deformation characteristics between the integrated retaining piles and conventional retaining piles within the foundation pit depth. Monitoring results indicate that after applying this technology, zero water seepage was achieved at the plugging location. The maximum pile deformation at the plugging position was 8.9 mm, and the maximum pile deformation across the full depth of the foundation pit was controlled within 39.6 mm. The study shows that this technology not only effectively resolves the water seepage problem associated with traditional pipeline plugging but also utilizes the friction between the pipeline and the surrounding soil to exert a counteracting force on the retaining structure. This significantly reduces the deformation of the retaining piles and enhances their stability. The technology demonstrates remarkable effectiveness in ensuring the quality of pipeline plugging and the safety of foundation pit excavation, holding high practical and promotional value for engineering applications.