Abstract: The effect of cold deformation (elongation and compression) and after deformation at different temperature temper on microstructure and mechanical properties of 15SiMn2Mo low carbon beinaitic steel were studied. The results show that after 10% pre-tensile deformation and different temperature temper,increase the temper temperature,tensile strength increased and reached the best value after 300℃ temper and equaled the hot rolling and low temperature temper in strength. The temperature in excess of 300℃,the tensile strength decreases and percentage elongation and area reduction increase. The compressibility coefficient increases and brings about work hardening and hardness increases and forms ferrite deformation bands in microstructure. After compressibility deformation and different temperature temper,the microstructure takes place recovery and recrystallization and forms refined equiaxed crystal grain,microstructure refinement and the compressibility deformation amount increases,refined effect increases.