Abstract: This paper introduces the derivation of rain load, the design of aeroelastic model of high-voltage transmission tower and wind tunnel test. Based on the existing production, an improved rain load formula is derived from a different idea and that the facade and rear of tower are considered to be impinged by droplets, and then programming is conducted to obtain the time history curves of wind-rain loads. According to the similarity criterion, the aeroelastic model for wind tunnel test is established, and the frequency of the aeroelastic model is measured and compared with the expected frequency which proves that the aeroelastic model is accurate. According to the rain load pressure calculation formula, the scale ratios of wind-rain loads for wind tunnel test are derived; the validation of theoretical calculation is performed through the wind tunnel test and the result proves that the theoretical calculation is feasible and effective.