The non-mandrel hot spinning process of TC4 titanium alloy high-pressure gas cylinders under different process parameter conditions was simulated by DEFORM finite element software, and the influences of spinning temperature, feed ratio and roller fillet radius on the plastic properties during the forming process were studied. The results show that when the spinning temperature increases, the equivalent stress on the gas cylinder surface during the forming process decreases, but the equivalent strains at each sampling point are basically the same at different temperatures. When the feed ratio decreases, the equivalent strain increases, and the effect on the equivalent stress is significant. When the feed ratio is 3 mm·r-1, the stress value changes are relatively uniform between the sampling points. The smaller the fillet radius of roller, the greater the reduction degree of equivalent stress in the depth direction, the change of the equivalent stress caused by the roller on the surface of gas cylinder is great when the radius R is 60 and 80 mm, and the change of the equivalent stress is small when R is 100 mm and the workpiece has better uniformity. In conclusion,  the optimal hot spinning process parameters for TC4 titanium alloy high-pressure gas cylinders are the temperature of 950 ℃, the feed ratio of 3 mm·r-1, and the roller fillet radius of 100 mm.