Based on the data of China’s A-share manufacturing listed enterprises from 2009 to 2017，this paper studies the impact of financialization on enterprise innovation from the ambidextrous perspective of innovation investment and innovation efficiency，and further analyzes the heterogeneous effect in different internal and external environments. It is found that financialization significantly inhibits the innovation investment and innovation efficiency of enterprises. Compared with the low uncertainty of economic policy，the negative effect of financialization on innovation investment is stronger while the inhibiting effect on innovation efficiency is weaker in years with high uncertainty of economic policy. Customer concentration can relieve the inhibition of financialization on innovation efficiency，while financial flexibility can relieve the inhibition of financialization on innovation investment. Further analysis shows that there is a threshold effect on the impact of financialization on innovation investment，namely， there is a reasonable fluctuation range of financialization level，in which the “crowd-out effect” of financialization on innovation investment is the smallest. However，there is no evidence to show that there is a threshold effect of financialization on innovation efficiency. In addition， financialization will exert far-reaching and indirect effects by inhibiting the contribution of innovation investment to the promotion of total factor productivity.