Enterprise innovation activities need sufficient sources of capital, and equity pledge has gradually become an important way of financing. What impact will equity pledge of venture capital bring on enterprise innovation? Taking the listed companies of China's SME board and GEM from 2007 to 2017 as the research object, this paper empirically examines the relationship between equity pledge of venture capital and enterprise innovation. It is found that the pledge of venture capital equity will inhibit the innovation of enterprises. Mechanism analysis shows that pledge of venture capital equity will improve enterprise financing constraints, thereby inhibiting the enterprise innovation. Further research shows that in enterprises with low level of internal control and small scale of independent directors as well as enterprises in non-state-owned and high-tech industries, pledge of venture capital equity has a greater inhibitory effect on innovation.