Introduction Cardiac rehabilitation (CR) is a critical treatment for patients with coronary heart disease after percutaneous coronary intervention. Unfortunately, participation and adherence of CR are unexpectedly poor. This study aims to test whether low-intensity or medium-intensity brisk walking is more helpful in improving early attendance, adherence and physical results. Methods and analysis This randomised controlled study will compare the effects of low-intensity and medium-intensity brisk walking to improve adherence and cardiopulmonary endurance. Participants will be randomly allocated to low-intensity or medium-intensity groups and will be followed-up for 8 weeks. Primary and secondary outcome data will be collected at baseline and at 2, 4 and 8 weeks. Primary outcomes measure changes in oxygen consumption (VO2) peak value (mL/kg/min), as well as adherence. Secondary outcomes include changes in body mass index, oxygen pulse, maximal metabolic equivalent, breathing reserve, vital capacity, ratio of forced expiratory volume in 1 s to forced vital capacity, Delta oxygen consumption/Delta work rate (Delta VO2/Delta WR), minute ventilation/carbon dioxide production and self-efficacy. Ethics and dissemination Ethical approval and informed consent form have been obtained from the Ethics Committee of Hebei General Hospital (approval number: NA-2021-03). The study background and main objective, as well as potential benefits and risks, will be fully explained to the participants and their families. Findings from this study will be published on academic journals in Chinese or in English for widespread dissemination of the results