Based on the quasinatural experiment of fiscal support for deepening the construction of pilot cities for the comprehensive reform of financial services targeting private, small, and microenterprises, this paper employs a difference in differences model to empirically examine the impact of the pilot policy of fiscal support for inclusive financial reform on the high quality development of private enterprises and its underlying mechanisms. The findings show that this pilot policy significantly promotes the high quality development of private enterprises. The mechanism tests indicate that the pilot policy has served the dual functions of relieving hardship and boosting confidence, which promotes the high quality development of private enterprises by alleviating financing constraints, reducing institutional transaction costs, and increasing innovation awareness. Further analysis demonstrates that the policy effect of promoting high quality development through fiscal support for inclusive financial reform is more pronounced for private enterprises with unstable resource access expectations, and the improvement in the quality of the institutional environment synergistically strengthens the policy effect. This paper illustrates how to improve the major sector of inclusive finance and efficiently support the highquality development of private enterprises from the lens of leveraging fiscal funds to effectively guide the structural reform of the financial supply side, which provides constructive insights into how the promising government can optimize fiscal and financial synergy policies to enable an effective market.