Aiming at the reasonable arrangement of prefabricated building project procedure, an optimization method of procedure based on Quantumbehaved Particle Swarm Optimization (QPSO) is proposed in this paper. The project process is first coded so that it can be expressed in quantum form. Then, based on the objective function considering the construction period and cost, QPSO algorithm is used to optimize the working plan to get the optimal solution. In addition, in order to improve the convergence ability of QPSO algorithm, a mutation mechanism is incorporated to avoid its falling into local optimum. The experimental results in a case of a prefabricated residential project show that the proposed method can effectively reduce the project duration and cost, and it has high practical value.