In the initial phase of the physics experiment, the double-null divertor plates usedconsist of graphite armor tiles, Mo-alloy intermediate layers and Cu-alloy coolant tubes. In thelater operating phase, tungsten will be used as armor tiles.A multi-physical field numerical analysis method is used in this paper. Its analysis modelreflects more realistically the real divertor structure than other models. Two-dimensional (2D)and three-dimensional (3D) fluid flow field, temperature distribution and thermal stress analysesof the divertor plates are carried out by the ANSYS code. During the physics experimental phasewith a heat flux of 1 MW/m2, a coolant velocity of 5.48 m/s, and a thermal stress of 750 kg/cm2,the graphite armor tiles successfully meet the requirements of temperature, thermal stress andsputtering erosion. The tungsten armor will be considered as a second candidate. The result ofsimulation can be used for upgrading the design parameters of the HL-2A poloidal divertor.