Based on the component of CSiMnCrMo hotrolled dualphase steel of 600 MPa grade, two test steels with different mass fraction of Si (0.55% and 1.17%) were designed. The CCT curves of the two test steels were measured by Gleeble3500 thermalmechanical simulator. The effect of mass fraction of Si on the phase transformation evolution of the test steels during the continuous cooling process was analyzed, and the effect of mass fraction of Si on the production process of mediumtemperature coiling hotrolled dualphase steel in short process was studied. The results showed that compared with w(Si)=1.17%, w(Si)=0.55% reduced the ferrite transformation temperature by about 4050 ℃, significantly shortened the incubation period of ferrite transformation and increased the volume fraction of ferrite. In the actual production of CSP line, the finishing temperature of the lowSi test steel can be controlled in 820830 ℃. The low finishing temperature increased the ferrite phase transformation time by about 2.2 s and the amount of ferrite transformation. Moreover, the occurrence of nonmartensite microstructure can be avoided in the subsequent phase transformation process. Therefore, the lowSi test steel was suitable for the production of mediumtemperature coiling hotrolled dual steel on the compact thin slab production line.