800 MPa class cold rolling hot dip galvanized dual phase steels based on low Si and CMnCrMo alloy system were pilot produced in laboratory. Effect of processing parameters including coiling temperature, annealing temperature and soaking time on microstructures and properties of dual phase steel were studied. The experimental results show that annealed at 820850 ℃,soaking time surpasses 100 s, tensile strength of experimental steel can reach above 800 MPa. The strength of experimental steel increases with the annealing temperature steps up. The synthetical mechanical properties of dual phase steel which annealed at 820 ℃ is the best. When annealed at 820 ℃, the strength of obtained steel dramatically increases with the soaking time. But when soaking time surpasses 100 s, the strength increases slowly. When the coiling temperature is 690 ℃, dual phase steel which has good mechanical properties can be obtained after annealing.