Abstract: The major factors, which correlate with the end face deformation of the mechanical seal ring, were analyzed.The method to calculate the coefficient of heat transfer between seal ring and medium，and the method to calculate the heat flux exerted on the end face were presented.For the high speed and over-load mechanical seal,thermal deformation is much more remarkable than the deformation caused by pressure.For a given seal ring model, it is possible to train a three-layer back propagation artificial neural network (BP ANN)to accurately forecast the relative thermal deformation Δz between outer diameter and inner diameter on the end face of the seal ring.The input samples were the heat flux values exerted on the end face of the seal ring and giren by the orthogonal design method.The output samples were the values of Δzthat were calculated by the finite element method.By means of BP ANN and the orthogonal design method, the high degree nonlinear relationship between heat flux and thermal deformation of the end face of the seal ring could be analyzed satisfactorily.