Abstract: Efficient integration of two markets and two resources at home and abroad is an important way to enhance the level of enterprise innovation.Based on the micro-data of listed companies from 2007 to 2021,this study systematically examines the impact of enterprises’ overseas market development on enterprise innovation and its internal mechanism from the dual perspectives of export and outbound investment.The results show that both export and OFDI promote innovation; Heterogeneity analysis shows that the overseas market expansion of non-state-owned enterprises, enterprises with a high proportion of overseas market and enterprises with low productivity are more likely to improve the innovation level of enterprises.Mechanism analysis shows that the effect of enterprise export and OFDI on promoting innovation can be realized through two ways: increasing R＆D investment and increasing the employment of technical personnel.Further comparative analysis shows that OFDI has a more significant promoting effect on innovation than export.