The performance of the compressor has a significant impact on the performance of the turbocharged diesel engine, which is also a major difficulty and focus of the simulation. The thermodynamic model of the compressor is clear in the principle, simple in the extensibility, but difficult in the acquirement of the model parameters. To overcome this difficulty, a method for optimizing and modeling the compressor characteristic parameters based on the particle swarm optimization (PSO) is proposed according to the experimental charts. Using the obtained characteristic chart of the compressor within a limited range, several parameters are selected as the optimization parameters of the model, including the inlet and outlet diameters, the impeller inlet angle, the diffuser inlet angle, the blade back angle, and the impeller outlet width. The simulation results of the optimized thermodynamic model are compared with the actual characteristic charts. The results show that the optimized thermodynamic model matches well with the experimental charts, expanding the applicable range of the operating conditions for the compressor model.