Insulators are the most widely used components in overhead transmission lines. Among them, the zero-value problem of disk-shaped suspended porcelain insulators seriously affects the safety and stability of transmission line operations. The mechanical properties of porcelain insulators are one of the important factors that determine their degradation rate. Among them, collision is one of the factors that affects the mechanical properties of porcelain insulators. In order to study the stress distribution level of porcelain insulators under collision conditions, a finite element simulation model of porcelain insulators was established, and the stress distribution of each component of porcelain insulators under knocking conditions was calculated and analyzed. The results show that: under knocking conditions, the risk of porcelain parts, steel caps and steel feet being damaged is small, while the risk of cement adhesive being damaged is greater, and the outer wall of the cement adhesive at the porcelain part-steel cap is knocked The risk of damage to insulators is greatest at the bottom of the recess.