The invention discloses a length optimization method for an express lane intersection area, comprising steps of (1) determining driving behavior parameters under an ice and snow condition, (2) simulating the express lane intersection area in the ice and snow condition, (3), performing variation tendency analysis on time occupation ratio of the express lane intersection area in the ice and snow condition, (4) establishing a time occupation ratio regression model of the express lane intersection area in the ice-and-snow condition, and (5) determining the length of the intersection area of the urban express lane. The length optimization method for the express lane intersection area considers affects of snowy road conditions like snow, ice plates, ice films, etc on the operation of the express lane intersection area, obtains the intersection area service levels under various ice and snow conditions, and can help people to choose the appropriate intersection area length according to the snow and ice condition in the road construction and design.