Taking the thin-walled Y-shaped tube as an example, the finite element modeling were performed. The Dynaform finite element simulation software was used to carry out numerical simulation of internal high pressure forming, and the forming rule, main defect form and defect location of the Y-shaped tube were discussed; the influences of process parameters, such as geometric morphology parameters, friction coefficient and loading path, on the forming quality were discussed. The wrinkling gap and film length were selected as logical control inputs to evaluate the state of forming; in order to optimize the loading path of Y-shaped tube high-pressure forming, the forming process was divided into four stages for fuzzy control system design. The results show that after the loading path optimization, the filling effect is greatly improved. The internal high pressure forming process and the fuzzy control system were applied to the Y-shaped manifold in an automobile exhaust system for structural improvement and forming process optimization,qualified parts to meet the quality was obtained.