The rapid motorization of cities leads to the increasingly serious imbalance between the supply and demand of road resources, the current timing control method of traffic signals cannot adjust the signal timing according to changes in traffic flow, thus reducing the efficiency of the road network. In order to optimize the timing of multiple traffic signals in the area, a solution method based on the improved firefly algorithm is proposed, the green light duration of each phase of the multi-intersection signal is used as a control variable, and a planning model with the minimum total delay in the region as the objective is optimized. Aiming at the problems such as the low optimization accuracy of standard firefly algorithms and the possibility of falling into a local optimum, a dispersal mechanism and mutation operations are introduced during the evolution of the population for improvement. Five standard test functions are used for experimental verification, experimental results show that the improved firefly algorithm can improve the accuracy and stability of the solution. Finally, taking a typical multi-intersection region as an example, the improved firefly algorithm is applied to the optimization problem of regional timing, and the effectiveness of the solution is proved through comparative experiments.