Abstract: In order to fulfill oilfield’s demand for developing the super-high temperature retardant, the recipe DHTR400 resisted 200 degree has been tested. This paper studies the synthetic process for DHTR400, the mechanism of delayed coagulation and then evaluates the effect of DHTR400 with various addition on mud thincking time, meanwhile, the sensitivity of DHTR400 to the temperature and its effect on compressive strength have also been inspected. The results indicate that DHTR400 is characterized by well temperature resistance ability, flexible thicking time, and little sensitivity to temperature. Under the condition of high temperature, the compressive strength of cement develops fast and smoothly, and features relatively high compression strength for cement rock.