TC4 titanium alloy seamless thick-walled pipe with φ108mm ×14.5mm×Lmm was prepared by industrial assembly line production through hot piercing, tube rolling and diameter reduction process of hot mandrel pipe mill. The mechanical properties and microstructure of pipe were analyzed. The results show that the TC4 titanium alloy seamless thick-walled pipe produced by hot rolling process has fine mechanical properties. The microstructure of the pipe shows deformed transitional microstructure. The microstructure is mainly composed of a large number of distorted lamellar α phase and a small amount of intergranular β phase, and a few small equiaxed α phase are distributed among them. Because of the large deformation, the size of β grain is not large, and the intra-crystalline α is fine. After heat treatment, the microstructure of the pipe changes from distorted and uneven deformation to uniform morphology. The inner α lamellar becomes long rod α, the grain boundary α recrystallized and spherodized to form globular α, and the non-continuous β grain boundary can be seen at macro level. The properties of the pipe are improved by solution aging treatment. The comprehensive mechanical properties of the pipe are Rm≥995Mpa, Rp0.2≥931Mpa and A≥15%, showing excellent performance.