Based on the context of China's unified national market, this study employs a combination of case study, empirical research, and policy analysis methods, selecting J City in Z Province as the case study to systematically analyze the implementation outcomes of the fair competition review system. The findings indicate that J City has continuously refined relevant policies and collaborated with multiple government departments, third-party institutions, and entities from the Yangtze River Delta region to carry out reviews, leading to significant improvements in market vitality and the business environment; however, local protectionist administrative monopolistic practices remain prevalent at the grassroots level, primarily due to ambiguous review criteria and insufficient mechanisms for performance evaluation and accountability.