To better understand the temperature field in the upsetting head of a titanium alloy rivet and its influence on the forming of ASBs, a three dimensional FE model was built on the ABAQUS platform, fully taking into consideration the strain hardening, strain rate hardening and thermal softening effect of the rivet material and friction and nonlinear behavior of the structure. Computation results show that ASBs experience a high strain concentration during the process and the high temperature zones coincide with the ASBs basically. It is observed that the temperature rise in the ASBs reaches to 500 oC, which means the highest temperature in the rivet exceeds its recrystallization?temperature