On the basis of numerous experimental results the effect of heat treatment on mechanical properties of TC4 alloy is studied. A computer model expressing the relationships between heat treatment and mechanical properties has been established with supported vector machine method. The input parameters were determined by the heating temperature and heating time which are important factors of the mechanical performance, and the output parameters are tensile and yield strength and elongation. The model is established by libsvm with RBF kernel function, e-SVR and proper parameters. Experimental results show that prediction accuracy made by using support vector machine reached over 95%, and the model has good learning precision and generalization and it can be used for predicting the mechanical properties of TC4 alloy.