Abstract: To explore the influence of the factor of the horizontal curvature on fuel economy, a vehicle eco-speed optimization algorithm based on the information of road curvature was developed. Firstly, with the aid of the establishment of the BIT-TFCM instantaneous fuel consumption model and vehicle dynamics model, the steady-state optimal speeds corresponding to various circular curves with different radii were obtained. When entering or departing a curve, the optimal speed profile can be calculated with the dynamic programming algorithm. The fuel consumption can be reduced by 5.69%~15.91% with this algorithm compared with typical driving model using the co-simulation of Matlab/Simulink and CarSim. This technique can obviously improve the vehicle fuel economy when running on curved roads, and can provide decision-making for speed control of unmanned vehicles.