Against the backdrop of increasing global trade policy uncertainty, ensuring the security of industrial and supply chains has become a strategic core for China’s construction of a new development pattern of “dual circulation”. A key issue is how micro-level enterprises perceive and respond to external shocks by adjusting their supply chain configurations to mitigate risks. Existing research often relies on macro-level indicators, overlooking firms’ subjective perceptions and the asymmetric strategies they may adopt for their upstream (procurement) and downstream (sales) chains. To fill this research gap, this paper utilizes the annual reports of China’s A-share listed companies from 2008 to 2022. By employing textual analysis, it constructs a firm-level index for the perception of trade policy uncertainty (TPU) to accurately capture the risk perception of micro-entities. The results show that a rise in perceived trade policy uncertainty leads to a significant asymmetric effect: Firms tend to drive the diversification of their upstream (supplier) configurations to disperse the risks of supply disruptions and price volatility, while simultaneously promoting the concentration of their downstream (customer) configurations to secure key sales channels and stabilize revenue sources. Mechanism testing indicates that this asymmetric adjustment of upstream diversification and downstream concentration is significantly amplified when supply-demand coordination costs are higher, relationship-specific investments are lower, or relative bargaining power is weaker. Heterogeneity analysis reveals that characteristics at the regional, industrial, and firm levels—such as the stickiness of collaborative relationships and supply chain information friction—also differentially affect firms’ supply chain adjustment strategies. From the micro perspective of firms’ subjective perceptions, this paper provides new evidence for understanding the impact of trade uncertainty on corporate behavior, systematically revealing the asymmetry of supply chain configurations and its underlying mechanisms. The conclusions not only offer practical guidance for firms in building resilient and flexible supply chain systems, but also provide an important reference for governments in formulating differentiated support policies to enhance the security of industrial and supply chains.