The temperature-coupled field analysis of liquefied petroleum gas (LPG) tank under fire is carried out based on wavelet finite element method. The wavelet finite element model is constructed through combing the heat conduct equation model and B-spline wavelet scale function. The temperature changing rules of LPG tank were obtained based on ANSYS software, wavelet finite element program, and test, respectively. The temperature changing rules of LPG and tank wall are obtained, and the effectiveness of the wavelet finite element method is verified.