Abstract:An efficient algorithm(Decrement-dimensional Precise Time Integration method, DPTI) of two-dimensional transient heat conduction equation is presented for Functionally Graded Materials(FGMs) based on the Precise Time Integration method (PTI). DPTI realizes the matrix storage optimization which solves the problem of large-scale coefficient matrix H when calculating the transfer matrix T which PTI surfers. DPTI also make full use of the similarity of the equation after decreased dimension to reduce the computation time greatly which achieve the optimization of the computational efficiency. The numerical examples are presented to demonstrate the effectiveness and reliability of the proposed method.