The invention discloses an expressway turning segment variable velocity-limiting control method. A traffic flow detector is installed on the downstream of an expressway turning segment. A road-side variable information prompt board is installed on the upstream of the expressway turning segment. An optimal uphill speed limit value on an expressway turning segment is chosen through calculation to propagation velocity of traffic jam waves. Consequently, the expressway turning segment variable velocity-limiting control method achieves the purpose that a driver can carry out variable speed control on the condition that the driver has poor sight distance on the expressway turning segment, enables the driver to slow down to the safety vehicle speed in advance before the driver drives a vehicle into the expressway turning segment, thereby avoiding rear-end collisions caused by traffic jam on the downstream. The expressway turning segment variable velocity-limiting control method is attached to actual traffic flow characteristic, is easy and convenient to implement, and has wide engineering value and good application prospect in preventing the rear-end collisions on the condition that the driver has poor sight distance on the expressway turning segment.