身体活动不足每年造成全世界超过500万人死亡，同时造成至少675亿美元的经济负担。我国职业人群身体活动不足问题已经凸显。工作场所身体活动促进面临诸多挑战，例如干预效果不明显、难以触及关键人群、评估系统性不强、可持续性和可推广性不足等。近年来新媒体技术的快速发展和智能手机的普遍应用，为行为干预技术在卫生领域的应用提供了新机遇。本研究首先通过横断面研究阐明职业人群身体活动的影响因素，然后引入圈层文化概念，以计划行为理论和社会支持理论为基础，创建身体活动干预新模式：以手机步数为核心指标，通过基于新媒体平台的团队竞赛和线上激励实现自我调控和互相监督的有机结合，塑造圈层运动文化，重构身体活动生态环境；最后开展随机对照实验研究，系统评价干预的短期和长期效果，并进行成本效果评价，探索适合我国工作场所文化语境且符合成本效益的干预模式，为我国制订工作场所身体活动促进措施提供新的理论和实践依据。

The pandemic of physical inactivity causes more than 5 million deaths worldwide and an economic burden of at least 67.5 billion US dollars every year. Physical inactivity among occupational population in China has been highlighted. Worksite physical activity promotion is facing many challenges such as having no obvious effect of intervention, being difficult to reach the key population, lack of systematic evaluation, sustainability and popularization. The rapid development of new media and widespread application of smart mobile phone in recent years provide new opportunities for the application of behavioral intervention technologies in the field of public health. This study aims to 1) clarify the potential determinates of physical activity among occupational population; 2) develop a new model of physical activity intervention based on the Theory of Planned Behavior, Social Support Theory and the concept of circle culture：3) realize the organic combination of self-regulation and mutual supervision, shape the circle sports culture, and reconstruct the physical activity ecological environment with steps recorded by mobile phones as the core index, through team competition and online incentive based on new media platform; 4) systematically evaluate the short-term and long-term intervention effect by randomized controlled trial, and cost-effectiveness by net benefit regression framework. The results of the current study will explore a cost-effective intervention model suitable for the cultural context of worksite in China, and provide a new theoretical and practical evidence for the development of worksite physical activity promotion in China.