Abstract: The effects of strain and heating temperature on the recrystallization behavior and phase transformation products of Nb-Ti microalloyed steel after deformation were studied by thermal compression experiment. The results show that when the heating temperature is 1100℃, the austenite grain size is not uniform, which leads to the uneven accumulation of strain in each grain during compression. The dynamic recrystallization occurs when the total strain is 0.380. When the austenitizing temperature are 1050 and 1000℃, the critical strain of dynamic recrystallization of austenite is 0.668 and 0.552 respectively. When the deformation temperature is 850℃and the strain is more than 0.552, the static recrystallization occurs at the pass interval; the cooling phase change microstructure of compressed samples after insulation at 1100℃is bainite and quasi-polymorphic ferrite.The grain size of polygonal ferrite in the sample is smaller (2-5 μm)after 1000℃austenitizing and compressing cooling transformation.