Abstract: Loose deposit slopes have caused severe disasters and casualties worldwide due to soil erosion, pollution, and instability triggered by both natural and human activities. In response to this serious threat, this study aims to review the theoretical and technological advances in regulating hydrological processes for slope ecological restoration, analyze their limitations and ecological impacts, and provide a foundation for sustainable ecological restoration and water management. By reviewing both domestic and international research, a theoretical framework for the hydrological regulation of deposit slopes was developed. Additionally, the application effects of various soil hydrological regulation technologies in ecological restoration, along with their impacts on slope components, were comprehensively analyzed. The advantages and limitations of existing hydrological regulation technologies were summarized, highlighting gaps in current research—such as the response mechanisms of vegetation water demand—and proposing future research priorities. Future studies should enhance research on the feedback mechanisms between hydrological processes and ecological restoration to address challenges in sustainable water management and to provide scientific support for regional ecological security.