Abstract: "People's livelihood" and "People’s support" constitute the essence of "paramount governance," with people’s sense of security serving as a critical nexus between them. This study constructs a theoretical framework for analyzing people’s sense of security and operationalizes it through comprehensive measurement using data from a nationally representative survey. By integrating individual and regional-level data, a multilevel model is developed to examine the effects of individual characteristics and developmental environment on people’s sense of security. The empirical results reveal that people’s sense of security is simultaneously shaped by both micro-level variables （demographics, socioeconomic status, and social attitudes） and macro-level factors. Specifically, economic growth and public finance expenditures （particularly those targeting People's livelihood improvement） play a protective and supportive role in enhancing people’s sense of security. However, these macro-level factors primarily exert their influence through mediating effects on social attitudes. Based on theoretical insights and empirical analysis, this study proposes that at the current stage, while continuously improving People's livelihood, enhancing people’s sense of security requires: （1） Strengthening integrated research on the mechanisms through which various factors influence people’s sense of security; （2） Utilizing the level and dynamics of people’s sense of security as key indicators for optimizing policies aimed at enhancing people's sense of fulfillment, happiness, and security;（3） Strengthening the management and guidance of public expectations based on multilevel factor analysis.