Synchronized hydraulic bulging forming technology on three-layer-metal tubes was studied. The possibility of three-layer-metal tubes formed by hydraulic bulging method was discussed and proved by elastic-plastic theory. The calculation formulas about the bulging pressure, the residual contact stress and the relationship between them were derived and the main process parameters were analyzed. Finite element analysis was carried out on bulging forming process using MSC. Marc. Practical bulging forming experiments were conducted and well compounded three-layer-metal tubes with tight interfaces were obtained. Through the comparison of the results of theoretical analysis, numerical simulation and practical experiments, proper parameters for the bulging process were obtained and the theoretical analysis was verified and proved.