Abstract: This paper presents a forward design method utilizing BIM for the hydraulic machinery in large-scale drainage pumping stations, aiming to manage the complexities associated with the multitude of equipment, substantial information exchange, and high collaborative design requirements. Drawing on large-scale Pumping station projects, the study investigates the BIM design standard system for the hydromechanical discipline from three aspects: project initiation and planning, base templates, and collaboration principles, utilizing Revit software. A modeling workflow for equipment is established, balancing geometric accuracy, information integrity, and model lightness. Furthermore, the application of BIM is explored for design optimization in areas including clash detection, integration with CFD simulations, mold fabrication, and 3D drafting. The findings aim to provide a valuable reference for BIM-based hydraulic machinery design in similar projects.