Rainfall weather can easily lead to problems such as wet and slippery pavement, reduced friction coefficient and low visibility, which directly affect the safety of highway traffic. With the continuous increase of highway mileage and travel vehicles, the probability of accidents in rainy weather is increasing. In order to reduce the occurrence of road traffic accidents under rainfall weather, improve the accuracy and timeliness of rainfall disaster warning and management, pro-vide a more accurate and effective basis for meteorological disaster risk classification, and carry out research on refined rainfall disaster risk classification scheme. This paper summarizes the existing rainfall disaster risk classification standards, constructs the meteorological disaster index model, and proposes a lean rainfall disaster risk classification scheme from three aspects : possibility, severity and sensitivity.