The institutional differences in different countries result in differences in the level of social responsibility of different nodes involved in the supply chain of multinational enterprises, which suppresses the value spillover effect of multinational enterprises between regions. By establishing an economic model, based on the spillover of brand value and consumer feedback of customer supplier social responsibility in the supply chain of multinational enterprises, the motivation and practical path of the disclosure mechanism of multinational enterprise social responsibility throughout the entire process are analyzed. The research results indicate that consumers'' perception of brand social responsibility creates a direct motivation for multinational corporations to strengthen their relative competitiveness through social responsibility. The full process disclosure mechanism of supply chain social responsibility pierces the "brand veil", opens up the supply chain social responsibility information channel for branded products, and forms a social responsibility incentive mechanism for multinational corporations within the supply chain. Based on theoretical results, specific suggestions have been proposed to promote the transformation of corporate social responsibility information disclosure from subject disclosure to process disclosure, guide multinational enterprises to implant social responsibility clauses in supplier contracts, and cultivate and strengthen consumer social responsibility awareness.