Abstract:The economic consequences of CSR is an important topic in theory and practice. Based on the stakeholder theory, this paper analyzes the mechanism of CSR on investment efficiency.This paper uses principal component analysis to build a comprehensive index of CSR. The CSR index is significantly negatively correlated with investment efficiency, which indicates that CSR can restrain over-investment and under-investment, and plays a more significant role in under-investment enterprises. The change of short-term CSR has no significant effect on investment efficiency. In the samples of internal stakeholders, non-state-owned enterprises and undeveloped areas, the impact of CSR on investment efficiency is more significant. The ability of sustainable development and the reputation of independent directors play an intermediary role, and the degree of earnings management has a direct impact on the investment efficiency. The research enriches the research on the economic consequences of CSR, expands the pre factors of corporate investment, and provides a meaningful reference for current enterprises to actively fulfill their CSR and improve investment efficiency.