Abstract: For a kind of low carbon micro-alloy steel, a thermal simulation test was conducted with samples of F+B+P microstructure and the effects of its cold deformation at room temperature on the distribution, size and composition of precipitates were investigated via a technological process for rapid heating and short holding time. The results indicate that the dispersity of the precipitates increases with the change in dislocation density which is influenced by the deformation at room temperature, while the size of the precipitates decreases to a certain extent. And the size of equiaxed grains decreases with increasing deformation at room temperature in view of their morphology. Also, the deformation at room temperature can expedite the vanadium precipitation to a certain extent because of its high solubility.