Abstract: Under the erosion and corrosion of internal fluid medium, the wellhead equipment is prone to corrosion and thinning defects, forming a potential risk of leakage. Because of its high stability and reliability, dry coupled piezoelectric sensing method can be applied to online monitoring and evaluation of wellhead corrosion. In the actual operation process, due to the change of fluid medium state and environmental temperature, the working temperature of the tested wellhead equipment changes, which will affect the accuracy of corrosion measurement. In this paper, aiming at the difficulties of wellhead corrosion monitoring under extreme temperature conditions, the influence of extreme temperature change on the sound velocity of steel and coupling material is analyzed. On this basis, a dry coupling piezoelectric sensing method and system based on temperature compensation is proposed, and verification experiment is carried out. The application results show that the dry coupled piezoelectric sensing corrosion monitoring system has high accuracy and stability in the working temperature range of wellhead equipment by using the wall thickness compensation algorithm based on real-time temperature measurement.