The strength and tightness of screw connection are two important technical indexes of oil well pipe. However, API standard thread products have some problems, such as incomplete structure, insufficient strength and air tightness at the screw thread, muffler support and so on, which can only be used in some common well conditions. For increasingly complex geological environment and well conditions, such as deep well, ultra deep well, high pressure gas well, heavy oil thermal recovery well, directional well, horizontal well, heavy corrosion well, etc., it appears to be unable to do what it wants Lost circulation occurs from time to time. Compared with the specific type of thread connection, the above two problems can be effectively solved. In the production of hot rolled seamless steel pipe, stretch reducing is the key process. Because metal deformation occurs in three-dimensional space in the process of stretch reducing, and is affected by complex factors such as pass, tension distribution and frame spacing, it is difficult to master the metal flow law, which is easy to cause uneven wall thickness and affect product quality. Therefore, this study hopes to use numerical simulation technology to analyze the wall thickness distribution during pipe diameter reduction, so as to achieve the purpose of "improving product quality, effectively controlling pipe end length and increasing metal production".