Introduction Providing smoking cessation treatment is an important intervention for tuberculosis (TB) patients. Mobile technologies, such as smartphone applications, have shown promising potential. However, there are few effective applications that could support TB patients in their efforts to quit smoking. To address this problem, we will develop a smartphone application 'QinTB' to help TB patients quit smoking, and we will evaluate the clinical efficacy of this application by using a randomised controlled trial (RCT). Methods and analysis This is a two-step study. In the first step, we will develop a smartphone application based on an interactive application of the transtheoretical model and protection motivation theory. Then, we will perform an RCT using a two-arm design; a total of 400 patients will be randomly assigned to the application group or the doctors' advice group; both treatments will be 6 months and follow-up will be 12 months; the primary outcome is the biochemically verified 6 month sustained abstinence rate; data will be analysed on an intention-to-treat basis. Ethics and dissemination This study was approved by the Ethics Committee of Beijing Research Institute for Tuberculosis Control and Prevention. We will disseminate the findings of this study through peer-reviewed publications and conference presentations.