In response to the demand of the high-efficient seamless processes for the urea tank of diesel engines SCR system, the pipe blank was subjected to two-passes of reverse flow spinning + shrinkage spinning necking to develop a urea tank that met the design requirements. At the same time, the influences of process parameters such as spinning temperature, spindle speed, feeding ratio and spinning path on the forming quality of spinning necking were explored by experiments. The experimental results show that the hot spinning necking is one of the effective technical approaches to achieve precise forming of 304 stainless steel urea tank. The optimal combination of process parameters is that the radial equal-spaced spinning path is used, the spinning temperature is 750 ℃, the spindle speed is 300 r·min-1 and the feeding ratio is 0.7 mm·r-1. Under this combination of process parameters, the tensile strength of the spun urea tank after solution treatment is ≥525 MPa, the specified non-proportional extension strength is ≥210 MPa, and the elongation is ≥36.8%, which meet the technical requirements. Finally，the internal pressure, air tightness and fatigue experiments are carried out on the spun urea tank, and the results all meet the expected technical parameters.