Although previous studies have examined the influence of directors’ network on innovation activities， they have not paid much attention to the internal path through which directors’ network influences innovation investment. Taking A-share listed companies from 2010 to 2018 as samples， it studied the impact of directors' network position on firms’ innovation investment based on the perspective of risk taking. The results show that central position and brokerage position of directors' network have positive impacts on firms’ innovation investment； risk taking exerts a masking effect between central position and firms’ innovation investment， and a partial mediating effect between brokerage position and firms’ innovation investment. Further research find that the positive impact of central position and brokerage position on innovation investment is mainly reflected in the network of non-executive directors and independent directors. The masking effect of risk taking is mainly reflected in the network of non-executive directors and independent directors. The partial mediating effect of risk taking is only reflected in the network of non-executive directors. The research findings reveal the risk taking mechanism through which directors' network influences innovation investment， enrich research on social network theory and governance effect of directors' network.