Objective To explore the mediating role of negative information attentional bias in interoception and pain catastrophizing among early-stage lung cancer patients after surgery, and to provide evidence for conducting precise postoperative psychological intervention. Methods From June to August 2025, a convenience sampling method was employed to recruit 268 patients who underwent surgery for early-stage lung cancer and attended outpatient follow-up visits or received care in the day ward within three months postoperatively. Then they were investigated by using a general information questionnaire, the Chinese version of the Pain Catastrophizing Scale (PCS), the second edition of the Multidimensional Assessment of Interoceptive Awareness (MAIA-2), and the Chinese Attention to Negative Inventory (ANI). A mediation model was subsequently constructed and tested. Results The participants′ score of PCS was(32.99±5.05) points, MAIA-2 was(112.98±14.64) points, and ANI was(30.04±7.22) points. The participants′ score of PCS was positively correlated with the score of MAIA-2 and ANI, and there was a positive correlation between the score of MAIA-2 and ANI (all P<0.05). Attentional bias toward negative information partially mediated the relationship between interoception and pain catastrophizing, with the indirect effect accounting for 18.87% of the total effect. Conclusions Pain catastrophizing among patients following surgery for early-stage lung cancer is at a medium and above level. In clinical practice, greater attention should be paid toward the psychological and cognitive status of this population, particularly the potential synergistic effect of heightened interoception and attentional bias toward negative information in amplifying pain catastrophizing. Healthcare providers are encouraged to implement a dual-target intervention approach combining "attentional control" and "cognitive restructuring" to mitigate the risk of pain catastrophizing and prevent the development of chronic postoperative pain syndrome.