This study is mainly based on Lipsky's street-level bureaucracy theory, and explores the factors that affect the implementation of welfare policies by street-level bureaucrats. In this study, the personal attitude of the street-level bureaucrats is the independent variable, policy cognition is the mediating variable, and policy implementation is the dependent variable. The study data gets from Ching-ying Shen (2015) "An action research on the development of a service network for at-risk families in Yilan county" raw data, and analyzed through multiple mediation modeling. The research results show that the personal attitude and policy cognition of street-level bureaucrats are important factors affecting policy implementation, and policy cognition has a mediating effect between personal attitude and policy implementation, the authors get conclusions and suggestions.