Abstract: An optimization model with three objectives is established to optimize the installation location and control parameters of the Unified Power Flow Controller (UPFC), and to improve the power loss, voltage stability and economic efficiency of power systems. A solution method based on Multi-Objective Particle Swarm Optimization (MOPSO) is proposed, which obtains a representative Pareto solution set through non-dominated sorting and an external archive. Taking the IEEE 30-bus system as the research case, the proposed method was compared with Differential Evolution (DE) and Sequential Quadratic Programming (SQP). The results show that MOPSO can obtain a well-distributed Pareto front and effectively improve the system performance.