Aiming at the natural icing flight test of a helicopter, combined with the helicopter’s flight characteristics, the determining principle of the test flight route under different meteorological conditions is analyzed. The CMA Weather Modification Centre designed the helicopter icing test flight scheme based on the cloud structure conditions of the model forecast and real-time monitoring, applied, and verified it in the field test in Urumqi, Xinjiang, in March 2018. The results show that the determination principle of the natural helicopter icing test flight scheme mainly considers the meteorological conditions of cloud icing, cloud macro and micro characteristics, helicopter characteristics, etc. According to the position of the icing area relative to the cloud area, the principle of entering the icing area from the cloud bottom or cloud top is considered. The design process of the aircraft icing flight scheme is established. The ice potential prediction system is used to carry out probability prediction 72 hours in advance. The cloud precipitation explicit prediction system is used to carry out cloud condition prediction 24 hours in advance. The satellite inversion products carry out ice accretion condition monitoring and early warning 3 hours in advance. The forecast and monitoring results show that the macro and micro conditions of clouds in the planned test are ideal, in line with the conditions for the formation of aircraft icing. In view of this cloud, we design a way to avoid the cloud bottom entering into the detection area and exiting from the cloud bottom. To complete the ice detection, we use multiple climbing and flying to find the supercooled water area in the cloud. In the actual flight, ice accretion and supercooled water are also detected in the cloud, which is an ideal design and application example of aircraft icing.