As a typical city in dryland, the contradiction between economic development and ecological protection is increasing in Bayannur City, which intensifies the fragmentation of ecological space. Ecological network is an effective way to couple landscape structure, ecological processes and functions from the perspective of landscape connectivity. The main purposes for constructing a landscape ecological network are to protect landscape sustainability, maintain habitat, and increase ecological connectivity. Identification and optimization of urban ecological networks guarantee the effective provision of urban ecosystem services and ensure the regional ecological security pattern. We selected the key ecological sources of Bayannur City through the importance of ecosystem services, the landscape core area and bridges, the lakes and wetlands with important ecological functions, and the nature reserves. Then we used the least cost path method to identify the potential ecological networks in Bayannur City and its surrounding areas. Three scenarios were developed to optimize the ecological network. Scenario 1 was increasing the ecological stepping stones; Scenario 2 was repairing the barrier points, and Scenario 3 was protecting the ecological pinch points. The three scenarios addressed the shortage of insufficient ecological nodes, inaccessible corridors and weak ecological flow in the current ecological network pattern, respectively. The best plan was chosen according to "cost of network construction" and "effect of landscape connectivity". The results showed that the current ecological network pattern in the study area consisted of 24 ecological sources, 44 corridors, 39 ecological barrier points, and 41ecological pinch points. Among the three scenarios, the Scenario 3 had the most significant improvement in ecological network connectivity and relatively low conservation costs. However, the new corridor in Scenario 1 was important for the migration and activities of Mongolian wild asses as well as biodiversity conservation and stopping the eastward migration of the western deserts. Therefore, the ecological network optimization process in Bayannur City should also focus on the construction and planning of ecological networks in the western desert and desert-steppe areas of the study area so as to promote the ecological network coverage in the whole area. The results are helpful to methodologically support the construction of ecological security patterns in dryland cities.