The heat conductivity in the FGM plate was expressed by exponential function along theheight direction of the plate,based on the plane steady heat conduction basic equation of the plate,the series analytical solution of the plane steady temperature fields of in the plate subjected to the dif-ferent constant temperature of boundary was derived by variable separation method.Compared withFEM,the maximum node temperature error of two methods was 0.86%.Through the numerical cal-culations,the plane steady temperature field distributions in the plate were obtained,and the effectsof material gradient parameters and the geometric composition of the plate on the temperature fieldswere studied.The main results show as follows:(1)The temperature field distribution in the plate issymmetrical to the axis y through the centroid.(2)With the increase of gradient parameter value,thehigh temperature zone in the plate is extended to the two sides and lower side of plate.(3)With thedecreasing of the plate height,central lower temperature distribution in the plate tends gently.Thus,the suitable selection of gradient parameter and geometric composition can meet the need of the de-sign,application and analysis of the thermal stress,and the analytical solution obtained can be usedas a reference standard for other approximate methods.