With the aggravation of population aging，we need to vigorously promote the construction of multi-level pension service system. This paper reviews the situation that welfare lottery public welfare fund has been invested in various types of pension projects in recent years，and deeply participates in the construction of pension service system. It summarizes the role of welfare lottery public welfare fund in promoting the integration of home-based pension and institutional pension，helping to improve the service ability of medical and pension integration，supporting the training of professional personnel in pension service，building smart pension，and leading the trend of social respect for the elderly.