Objective To identify the decisional conflicts and underlying mechanisms of adherence to traditional Chinese medicine（TCM） topical therapies among colorectal cancer patients undergoing chemotherapy from the perspective of behavioral economics, and to provide a reference for optimizing nursing decision support and intervention strategies. Methods A descriptive qualitative research design was employed.Semi-structured interviews were conducted with 15 colorectal cancer patients undergoing chemotherapy from April to June 2025.The interview data were analyzed using thematic analysis. Results Three themes and nine subthemes were identified:treatment trade-offs dominated by emotions and immediate experiences （present bias, optimism bias, and ambiguity aversion）; judgment patterns based on personal experience and external cues （herd effect, information avoidance, and anchoring effect）; and the impact of information presentation on risk perception and acceptance （loss aversion, availability heuristic, and authority effect）. Conclusion Colorectal cancer patients undergoing chemotherapy commonly experience decision conflicts in adherence to TCM topical therapies, driven by time preferences, experiential heuristics, and risk perception biases.Nursing staff should mitigate patients′ immediate perceived burden, optimize initial treatment experiences, standardize risk communication, and strengthen professional support, in an effort to ameliorate patients′ decision conflicts and promote their adherence.