Specialized, refined, differentiated, and innovative (SRDI) enterprises play a critical role in addressing weaknesses, strengthening competitive edges, and filling market gaps within industrial chains, serving as key drivers for manufacturing value chain upgrading and new quality productive forces development. From the government-enterprise-market resource-information interaction perspective, this study employs a PSM-DID model using 2015-2022 A-share manufacturing data to examine how China’s “Little Giant” policy for SRDI enterprises drives manufacturing value chain upgrading. Results show the policy accelerates firms’ climb up the “smile curve” via capital, talent, and digitalization, with resource concentration and signaling effects. Stronger impacts emerge in growth-phase and state-owned firms, and regions with robust innovation/business ecosystems. Spatial analysis indicates a siphoning effect on neighboring manufacturers within close proximity, transitioning to positive spillover effects beyond critical distance thresholds, particularly benefiting peer enterprises with comparable development levels. Policy synergy analysis further suggests amplified effectiveness when coordinated with smart manufacturing pilot programs and carbon trading pilot city policies.