In order to solve the problems of insufficient forming of complex box part in the single deep drawing, a precise hot forming process of deep drawing and gas bulging was proposed, and the shape and thickness of the formed parts could meet the design requirements. TC2 titanium alloy complex box part was selected as the research object in this research. The high temperature formability of TC2 titanium alloy was investigated at 550–800 °C and 0.001–0.1 s^-1. A set of mold for deep drawing and gas bulging at one time was designed. The forming process of the complex box part was simulated based on the finite element simulation software PAM-STAMP, and the optimized process parameters were obtained and verified by experiments. Results show that the simulation software PAMSTAMP can effectively predict the part defects during deep drawing and gas bulging. The process parameters and mold shape are ameliorated and verified by experiments. Complex box part with thickness and height meeting the design requirements can be obtained under the conditions of 800 °C and gas pressure of 2.5 MPa, which verifies the feasibility of the composite process of deep drawing and gas bulging.