Thunderstorm microbursts, which are sources of extreme wind loadings in nature, have caused numerous structural failures, especially collapses of transmission tower around the world. It is important to study wind field characteristics of thunderstorm microbusts from the perspective of wind-resistant design. In this paper, the three-dimensional wind field characteristics of thunderstorm microbursts were studied using computational simulation method. Firstly, the three-dimensional wind field of microburst was computational simulated using time-filtered Reynolds Averaged Navier-Stokes (RANS) numerical computational method. Then, the three-dimensional wind field characteristics including the wind distribution of wind velocity at different heights, the wind contours at lower altitude positions were studied in detail. The results indicate that the three-dimensional wind field of microbursts winds presents quite different characteristics at different heights and radial positions.