In view of the limitation of road expansion to alleviate traffic congestion， and the fluctuation of the service level caused by the network design， this paper establishes abi-lev-el programming model of continuous equilibrium network design considering level of service reliability under speed limit.The upper layer planning aims to minimize the sum of the total travel impedance and the investment budget of the network under the level of service relia-bility constraints， and the lower layer is the user equilibrium under speed limit.According to the established bi-level programming model， a genetic algorithm based on Monte Carlo is designed to solve the problem.Numerical examples show that under certain level of service reliability requirements， combined with reasonable speed limit strategy， the traffic system performance and travel quality can be guaranteed from the system and local perspective， and the efficiency of network traffic operation can be improved.