In order to study the evolution of aircraft wake vortices more deeply and precisely， and to ensure the safe operation of aircraft， the dissipation law of A330-300 aircraft wake at different temperature vertical decreasing rates is studied in this paper by numerical simulation. The shear stress transport （SST） k-ω turbulence model is chosen for the numerical simulation. The temperature field under five different temperature vertical decreasing rates is constructed， and the A330-300 aircraft wake flow field is compiled within the temperature field to realize the calculation under different temperature vertical decreasing rates. The reliability of the numerical simulation method is verified by comparing the numerical simulation results with the radar detection data. The results show that for general turbulence intensities， different rates of vertical decreases in temperature act mainly on the decay phase of the wake， affecting the evolution of the wake by changing the temperature inside and outside the wake.The smaller the temperature vertical decreasing rate is， the larger the rate of decrease of circulation in the wake vortex decay region is. The larger the vertical rate of temperature decreases， the larger the rate of tail vortex sinking is and the larger the distance between vortex cores after rapid dissipations is.