The invention relates to a correction method of a shape coefficient of a transmission tower in a wind-sand field. The correction method comprises the following steps of arranging a sand supplying device and a sand collecting device on a wind tunnel test field to simulate a wind and sand two-phase flow wind field; establishing a wind tunnel test model and determining the shape coefficient of the test model under the effect of wind pressure only according to a wind tunnel force measuring test; carrying out a force measuring test of the test model in the wind and sand two-phase flow wind field under the condition of the same wind speed and a certain sand rate in the wind tunnel test; determining the shape coefficient of the test model under the effect of wind and sand two-phase flow; and determining the shape correcting coefficient of the test model under the effect of the wind and sand two-phase flow according to the shape coefficient of the test model under the effect of the wind pressure only and the shape coefficient of the test model under the effect of the wind and sand two-phase flow. According to the technical scheme, the shape coefficient of the transmission tower under the effect of the wind and sand two-phase flow can be calculated accurately.