To explore the impact of a collaborative management for couples based on KING's Goal Attainment Theory on the health outcomes of post-percutaneous coronary intervention (PCI) patients with coronary heart disease (CHD). This RCT involved 194 eligible patients, randomly assigned to either a control group or an intervention group. The control group received routine care and follow-up, while the intervention group received KING's Theory-based couple-focused case management in addition to routine care. The intervention comprised pre- and post-discharge sessions, containing dyadic goal-setting and dyadic health management strategies, fostering collaborative decision-making between the patient and their spouse. Outcomes were measured at T0 (2 days post-stabilization), 1 month, and 3 months post-discharge. The mean age of the participants was 61.3 (SD=12.0) years. Baseline data were similar in both groups. The intervention significantly improved chronic disease management self-efficacy (β=1.175), medication adherence (β=0.834), healthy diet adherence (β=1.127), exercise adherence (β=1.206), and was associated with the improvements of total cholesterol (β=-0.293), triglycerides (β=-0.280), and low-density lipoprotein (β=-0.229). All p < .05. However, the difference in high-density lipoprotein levels (β=-0.012), the rate of revascularization, recurrent angina pectoris, in-stent restenosis, and left ventricular ejection fraction (Z = -0.667) between the groups was not significant, all p > .05. The collaborative management for couples based on KING's Goal Attainment Theory significantly improved self-efficacy and adherence to lifestyle changes of post-PCI patients with CHD, and was associated with the improvements of the lipid profiles. Future studies could investigate the cost-effectiveness and long-term impact of this theory-based intervention. Chinese Clinical Trial Registry (ChiCTR) ChiCTR2400085183.