A legalized business environment is the cornerstone for the healthy development of the private economy. This article analyzes the challenges and opportunities faced by the current development of the private economy, focuses on elaborating the necessity of optimizing the legal environment and protecting the rights and interests of private enterprises and private entrepreneurs in accordance with the law, and proposes measures to build a fair and just legal environment. The aim is to provide a solid legal guarantee for the healthy and high-quality development of the private economy,and thus promote the sustainable development of the socialist market economy with Chinese characteristics.