Introduction People who are eager to quit smoking often lack long-term, daily smoking cessation guidance. In addition, advances in mobile communication technology offer promising ways for providing tobacco dependence treatment. However, it is unclear whether the doctor-WeChat network can improve the smoking cessation rate of nicotine-dependent patients. Methods In this prospective single-blind cohort study, 250 smokers were enrolled from May 2018 to October 2018. They were randomly divided into two groups, with or without doctors' active smoking cessation service, and followed up for 6 months. The smoking cessation rate and characteristics of successful smoking cessation groups were compared. The reasons for relapse were also analysed. Results After smoking cessation for 3 months, the success rate of the group involving active respiratory physicians was 65.0% (80/123), whereas the success rate of the control group was 34.7% (34/98). After 6 months, the success rate of the group involving active respiratory physicians was 55.3% (68/123), while that of the control group was only 11.2% (11/98). There was no difference in the weight change of the participants between the two groups. Subgroup analysis showed that doctors' participation had a greater impact on the success of smoking cessation in men younger than 45 years or unemployed. Conclusions Doctors in mobile smoking cessation services played a very important role in improving quit rates. Our research provided methodological guidance for further clinical trials and a template for further real-world applications of smoking cessation services.