The construction of ecological security patterns is beneficial for mitigating ecosystem degradation and biodiversity loss, and is of great significance to biodiversity conservation. For the identification of ecological sources, existing studies are relatively subjective and the boundaries of sources are broken, lacking objective identification of ecological sources based on mutation points. In addition, the contribution of the ecological corridors to landscape connectivity is still not clear. Taking the urban belt along the Yellow River in Ningxia as an example, first, we evaluated four ecosystem services of habitat quality, carbon sequestration, soil conservation, and windbreak and sand fixation, and used the spatial continuous wavelet transform to identify mutation points of comprehensive ecosystem services to obtain ecological sources. Then, we evaluated the functional connectivity based on the circuit model to extract ecological corridors and got the spatial distribution of ecological security pattern. Finally, we quantified the contribution of ecological corridors to landscape connectivity. The results showed that 27 ecological sources were identified, covering an area of 9192.51 km², accounting for 41.51% of the total area of the study area, with grassland accounting for 83.27%, and its comprehensive ecosystem service value was 1.20. The mutation points identified by spatial continuous wavelet transform could better identify the boundaries of ecological sources according to the actual ecological characteristics of the study area and had a high degree of consistency with the actual landscape. Compared with directly extracting the high-value areas of comprehensive ecosystem services, the ecological sources identified based on spatial continuous wavelet transform reduced the landscape shape index and fractal dimension by 67.20% and 8.06%, respectively, indicating that the latter had shorter edge length and more regular shape, so they were less likely to be disturbed by the surrounding environment. Ecological corridors had higher current value, and the total area was 1642.50 km², accounting for 7.42% of the total area of the study area, which was mainly distributed in the Yellow River and the grassland and bare land in the south of the study area. Ecological corridors were key channels for species migration and other ecological processes and had effectively improved regional landscape connectivity, increasing the equivalent probability of connectivity index and the equivalent integral index of connectivity by 41.76% and 68.68%, respectively. The ecological security pattern was mainly located at the boundaries of the study area, with an overall distribution of two belts, and the central part was connected by the Yellow River, which blocked the surrounding desert for the urban belt along the Yellow River in Ningxia and ensured urban development and food security in the central region. However, only 23.45% of ecological security pattern was located within nature reserves, indicating that there were still relatively serious gaps in the protection of ecosystem services and functional connectivity in the nature reserves within the research area. The ecological security patterns of each region had different ecological functions, which required the targeted and differentiated protection, restoration and management. The study provides a new methodology for the identification of ecological sources and quantifies the importance of ecological corridors. Identifying and protecting ecological security pattern is an important measure to ensure ecosystem integrity, ecological security, and sustainable development.