In the past,the numerical simulation of the premium connection seal of the oil casing was carried out on the basis of the smooth plane,which could not truly reflect the load contact condition during oil pipe connections.The Monte Carlo method was used to establish a contact model of the sealing surface of the tubing considering the roughness,and the effects of surface roughness,spherical radius of the joint female buckle and internal pressure load on the performance of the sealing surface of the tubing were analyzed.The results show that under the same interference,the smaller the roughness of sealing surface,the smaller the average contact pressure.The larger the radius of the spherical surface of the female buckle,the longer the contact length of the sealing surface and the higher the fit.With the increase of internal pressure,the number of contacts between the microconvex body and the cone surface on the contact surface of the buckle seal gradually increases,and in the case of mutual contact,the degree of elastic deformation gradually decreases,while the plastic deformation increases.Due to the increase in the contact length,the sealing surface has good sealing performance.