Abstract: From the perspective of social welfare, this paper draws on the construction methods and ideas of relevant domestic and foreign papers on composite indexes, and is inspired by the literatures on economics, astronomy and sociology. Based on the basic principle in the world lottery industry and rooted in the real actual situation on economy and lottery industry in China, we further improve the existing research, so as to construct a set of scientific, comprehensive, accurate and perfect sports lottery sales composite index system in China. The paper finds: the current social welfare effect of sports lottery in China is imbalance; sports lottery and welfare lottery are basically complementary; the two major policies of“the Ban of the Internet Lottery in 2015”and“the Adjustment on Fast & Toto Lottery in 2019”are both effective and limited. We put forward the following suggestions: Sports Lottery Management Center of General Administration of Sports of China and its branches in provinces should establish the issuance goal of optimizing the social welfare effect, reverse the imbalance of the social welfare effect with the index system in this paper,and construct a precautionary mechanism for risk in advance and an adjustment mechanism timely in process during the course of issuing and selling sports lottery; unite welfare lottery to optimize the Chinese public lottery industry; join hands with other government departments to crack down on illegal gambling.