Split wellhead adopts single-layer or double-layer casing head, the bottom is welded and connected with “O” ring, and it can be equipped with a round bottom support disc. The secondary seal can adopt “BT”, “P-type”, “BES” and other types of seals. The seal is safe, reliable and easy to operate. The tubing hanging adopts the mandrel type, which relies on the extrusion of the top wire to excite the rubber seal. The valve on the Christmas tree uses a dark rod and a sealed structure behind the valve. It has the characteristics of small switching torque and easy online maintenance.