New hydraulic bulge method and estimated conjoint results were explored. The equipment’s overall water pressure test is developed to get lining bulge and plastic deformation, to eliminate the gap between lining and shell. Integrated effect was estimated by measured layer gap, stress and strain through hydraulic bulge and pressure increase test. Test results show that: although the preliminary gap is not uniform, even 14~16 mm at some points, but the remnant is only 0.6~0.9mm after hydraulic bulge; cylinder always keeps elastic during the pressure increase test, and the linearity between cylinder strain and initial pressure is more than 0.99 after hydraulic pressure expanding treated; Lower temperature annealing of sheath did not have negatively affect on conjoint effect. It is a new technology with simplicity, safety, low production cost, and no pollution, which will create a new way of metal compound forming.