In order to improve the output performance of direct methanol fuel cell, the finite-time thermodynamic model of direct methanol fuel cell is developed in this paper. Then, mathematical expressions for energy efficiency, power density, exergy efficiency and exergy coefficient of performance are derived. In addition, the effects of operating temperature, inlet pres-sure and membrane thickness on the performance of direct methanol fuel cells are considered. The results show that the exergetic performance coefficient not only considers the exergy loss rate to minimize the loss, but also the power density of the direct methanol fuel cell to maximize its power density and improve its efficiency. Therefore, the exergetic perfor-mance coefficient is a better performance criterion than conventional power and efficiency. In addition, increasing the inlet pressure and decreasing the membrane thickness can significantly improve the exergetic performance coefficient and en-ergy efficiency.