The construction of a unified national market is a core strategy to smooth the domestic cycle and promote high-quality development. Taking the Yangtze River Delta (YRD) region as the research object

this paper systematically combs through 128 market integration policy documents issued by Shanghai

Suzhou

Zhejiang and Anhui in 2019-2024

and applies text mining and comparative analysis method to reveal the regional policy synergy characteristics and differentiation strategies. The study finds that: (1) the policy objectives of the three provinces and one city converge

but the implementation paths diverge - Shanghai focuses on the construction of digital governance platforms

Jiangsu focuses on cross-regional collaboration of industrial chains

Zhejiang explores the mechanism of private economic empowerment

and Anhui strengthens the infrastructure connectivity; (2) there is a tendency of "focusing on planning but not on implementation" in the policy tools

and cross-provincial disputes have a tendency of "planning but not on implementation"; (3) policy tools have the tendency of "planning rather than implementation"

and the coordination mechanism for cross-provincial disputes is missing; (4) local protectionism presents hidden characteristics

which is manifested in regional technical standard barriers and government procurement tilting. Based on this

optimisation proposals such as "policy implementation effectiveness evaluation system" and "inter-provincial interest compensation mechanism" are proposed to provide practical reference for the construction of a unified national big market.