Based on the quasi-natural experiment of "reverse mixed ownership reform", two types of strategic emerging industries, namely high-tech, energy conservation and environmental protection where "reverse ownership mixed reform" is common, were taken as research objects, to test the influence of “reverse mixed ownership reform" on green innovation of private enterprises. The results show that "reverse mixed ownership reform" can promote green innovation of private enterprises in strategic emerging industries. The mechanism test show that "reverse mixed ownership reform" has the "dual effect" of developing specialization and easing financing constraints, which is conducive to promoting the "moat" and "reservoir" of green innovation development of private enterprises. Based on the comparative analysis of representative industries, it is found that the reasonable design and strengthening of environmental regulations can effectively promote the synergistic effect of "reverse mixed ownership reform" on green innovation of private enterprises in high-tech industries, and the moderate strengthening and incentive of innovation subsidy policy can effectively promote the complementary effect of "reverse mixed ownership reform" on green innovation of private enterprises in energy conservation and environmental protection industries. These conclusions reveal the influence law of " reverse mixed ownership reform" on promoting green innovation of private enterprises, and provide theoretical and policy inspiration for promoting the high-quality development of strategic emerging industries.