Thermal blooming is an important nonlinear effect when laser beam propagates through atmosphere. The laser energy will be absorbed by the atmospheric molecular and aerosol particles, and the thermal expansion of the atmosphere will occur. It will lead the local atmospheric refractive index reduced. This effect distorts the laser beam and the transmission characteristic of laser beam is affected. In this paper, the thermal blooming effect of pulse vortex beam is discussed. And a numerical simulation is performed to simulate the light intensity of the pulse laser at different distance. The effect of different topological charge on thermal blooming effect is analyzed.