Promoting high-quality economic development is the goal of China’s macroeconomic policy in the current period and near future. To improve the efficiency of state-owned enterprises (SOEs) and broaden the development scope for private enterprises to achieve a simultaneous development of both SOEs and private firms in the mixed-ownership reform is undoubtedly an effective way to implement high-quality economic development. The executive meeting of the State Council has decided on Nov. 27th, 2019to make further steps to improve the business environment. One week after, on Dec. 4th, the CPC Central Committee and the State Council published ″The Guideline for Fostering a Better Environment to Support the Reform and Development of Private Enterprises″, which focused on the construction of business environment through marketization, institutionalization and internationalization, and the large opening up of economic sectors for private enterprises. This has provided an opportunity for a wide and substantial progress of mixed ownership reform, and the state and non-state owned economy will simultaneously grow in the reform through joint-stock cooperation. Now China has a state-owned, private-owned and foreign-owned ownership structure in the economy system, in which the non-state part, including private-owned and foreign-owned economy, has provided the motivation for innovative development, realizing substantial progresses in employment and people’s livelihood, nurturing and strengthening the enterprises and entrepreneurship in the economic development. As China has reached the level of a middle-income country, the challenge of middle-income trap and many other structural problems in the economy have gradually become more and more prominent. Recently the global rise of protectionism and unilateralism and the escalation of the trade war between China and the USA have joined forces with the economic slowdown in China, resulting in a downgrading of the traditional scale expansion development model that relies heavily on investment and export.Entrepreneurship has showed signs of shrinkage. China needs an urgent internal economic rebalance to achieve a structural transition, which can promote new motivations, transform and upgrade traditional motivations for a high-quality economic development. The promotion of mixed-ownership reform is to reform the state-owned economy with the competitiveness of the private economy, and incite a widespread social development of entrepreneurship, which are beneficial for the growth of new motivations as well as the transformation of traditional motivations. Solving structural problems with mixed-ownership reform will undoubtedly drive the sustainable growth of China’s economy to achieve the macroeconomic policy goal of high-quality development. The paths and approaches of the mixed ownership reform should now focus on these aspects: First, break the long-standing monopoly of SOEs in resource industries, and the cancel the SOEs’ monopoly privilege in certain markets. Second, fasten the marketization reform of public services, and provide better conditions for private enterprises to enter these areas. Third, reform the large and unified bank system, and create an economic system with bank industry and private enterprises collaboratively supporting the mixed ownership reform of SOEs. Eventually, the mixed ownership reform will solve the structural problem in China’s economy, activate the industrial network, market network, intellectual network and resource of SOEs, and release the resource and entrepreneurship of private enterprises and private investors, which can promote the innovative development in China and elevate China’s competitiveness, realize the high-quality economic development in China.