Electrical connector is a key interface element for the converter system to run well. To improve the contact reliability of the electrical connectors, structural mechanics analysis and mating process simulation for common spring contact were implemented. The contact force and the stress distribution of female cylindrical contact in the heavy load connector were obtained. Three essential tests were carried out on four kinds of contacts with different structures and metal finishes to figure out the quantitative differences in their contact performance. The results of contact force were compared from numerical simulation, theoretical calculation and experimental test, which verified the feasibility of the simulation method. The vibration reliability of European connectors manufactured by distinct companies was discussed by experiment, and the weak direction of the symmetrical spring contact under vibration was pointed out.