Effective allocation of multiple types of resources in large-scale construction projects is a key issue facing project management theory and engineering management practice at this stage. This paper constructs a system dynamics model of resource allocation for construction projects, and builds a resource allocation optimization model for construction site of construction projects with BIM and genetic algorithm, uses NSGA-III genetic algorithm to solve the model to obtain the Pareto frontier solution set, and adopts the method of distance between superior and inferior solutions (TOPSIS) to obtain the optimal solution, and verifies its feasibility and validity in the actual cases. The simulation results show that the insufficiency of funds and materials will directly produce a large schedule deviation, while the sufficient amount of funds and materials, although it can guarantee the construction progress to a certain extent, if it cannot be reflected in the number of labor and machinery, it will cause mismatches in the number of labor, materials and machinery, which will affect the efficiency of resource allocation. The NSGA-III genetic algorithm used in this paper can effectively solve the problem of optimal allocation of multi-project resources, and there is a significant reduction in the variance of resource consumption after configuration optimization. In addition, the degree of harmony of multi-project resource management using the method of this paper reaches the excellent level, which verifies the high efficiency of the model of this paper in the resource allocation in the construction site of a building project.
