The invention relates to a supporting mechanism of a wind tower transport vehicle. The supporting mechanism is arranged on the transport vehicle; the supporting mechanism comprises a first cylinder seat connected to the transport vehicle, a first cylinder rotatably connected to the first cylinder seat, a first rocker arm connected to the first cylinder, and a first supporting wheel connected to the upper end of the first rocker arm; the supporting mechanism also comprises a second cylinder seat connected to the transport vehicle, a second cylinder rotatably connected to the second cylinder seat, a second rocker arm connected to the second cylinder, and a second supporting wheel connected to the upper end of the second rocker arm; the lower ends of the first rocker arm and the second rocker arm are rotatably connected to the same rocker arm seat; and a wind tower is placed between the first supporting wheel and the second supporting wheel. The hydraulic cylinders are arranged on the transport vehicle, and the supporting wheels are fixed by using balance blocks, so that processes are reduced in the loading and unloading processes of the wind tower, the transport efficiency is increased, and a wind tower body and a surface coating are effectively protected in the transport process.