This study aimed to assess the levels of physical activity (PA) in people with chronic obstructive pulmonary disease (COPD), investigate the impact of dyspnea-related kinesiophobia on them, and further examine the moderated mediation effects of exercise perception and exercise self-regulatory efficacy on this relationship. This cross-sectional study was conducted from December 2023 to May 2024. Data were collected using the Breathlessness Beliefs Questionnaire, International Physical Activity Questionnaire - Long Form, Exercise Benefits/Barriers Scale, and Exercise Self-Regulatory Efficacy Scale. Descriptive statistics and Process macro in the SPSS program were used for data analysis. A total of 239 patients with COPD were included, and median physical activities were 64.50 (28.00, 126.55) MET-h/week. Dyspnea-related kinesiophobia was negatively correlated with exercise perception, exercise self-regulatory efficacy, and PA (r = -0.503, -0.739, -0.657, P < 0.01). Exercise self-regulatory efficacy partially mediated the impact of dyspnea-related kinesiophobia on PA (β = -0.255, 95% CI [-0.353, -0.164]), and exercise perception moderating this mediating pathway (β = 0.100, P = 0.030; β = 0.412, P < 0.001). People with COPD commonly have dyspnea-related kinesiophobia and experienced physical inactivity. The moderated mediation model provides a better understanding of how dyspnea-related kinesiophobia, exercise self-regulatory efficacy, and exercise perception work together to influence PA. Interventions seeking to improve the levels of PA in patients with COPD should consider these elements.