Abstract: The paper drew a comparison between the Fowler-Nordheim (FN) field emission current density which is applicable at low temperature and the general integral expression for field emission current density. A slender cylindrical microprotrusion model was adopted, two main factors－joule heating and heat conduction were both taken into account, and the temperature distribution in microprotrusion and the time-dependence of temperature at different points on microprotrusion were obtained using the code developed by ourselves. The results show that it is necessary to consider the influence of temperature effect of field emission on explosive electron emission. The temperature in microprotrusion increases nonlinearly with time when the temperature effect is included, and the increasing rate of the temperature grows more and more quickly. At low microwave electric field, the time delay of explosive electron emission will be shortened if the FN current density of electron emission is used instead of the general integral expression which can include the temperature effect of field emission; the temperature effect has little influence on time delay of explosive electron emission at high microwave electric field.