To improve the sealing grade of the large diameter high temperature and high pressure sleeve control valve,a new type of large diameter high temperature and high pressure sleeve control valve with new sealing structure was designed.The valve sealing structure is divided into upper and lower parts.The upper part adjusts the sealing position through the spring pre-tightening force and automatically adjusts the sealing coincidence.The lower part is sealed by the spool and the lower seat.The upper and lower parts are structurally coordinated to seal at the same time.The simulation analysis of static strength shows that the maximum stresses of the control valve is 204.1 MPa,the local stress of pressure plate,spring and the upper valve seat structure is 40.26 MPa.Both of which are less than the yield strength of the material,and the static strength meets the requirements.The simulation analysis of fatigue strength shows that the fatigue strength of the control valve meets the requirements in the life time.The fluid flow simulation analysis shows that under the small opening 30% working condition,the maximum fluid velocity in the valve cavity is 554.240 m/s,the maximum pressure is 1.706 MPa,and the maximum temperature is 252.50 ℃.Under the large opening 80% working condition,the maximum fluid velocity of the valve cavity is 501.736 m/s,the maximum pressure is 1.717 MPa,and the maximum temperature is 259.99 ℃.The results are consistent with the fluid flow characteristics.The pressure test of the valve body and the high pressure sealing test of the valve seat show that there is no visible leakage or deformation in the valve body.The leakage grade of the high pressure sealing of the valve seat is VI,which meets the requirements for the pressure strength of the valve body and the sealing performance of the valve seat.