<p>Rumor has a negative impact on people’s lives, which may further disrupt social stability and lead to adverse effects on society. However, traditional models typically assume that rumor disseminates within a single social network, which fails to fully consider the complexity of propagation mechanisms in coupled social platforms in reality. A new rumor propagation model UI_wI_cR is presented to accurately simulate the propagation dynamics of rumors in two-layer coupled networks, which consider the influence of internet water armies in rumor spreading. The propagation dynamics equation is constructed by microscopic Markov chain approach, and the spreading outbreak threshold is analyzed and proved. Furthermore, the effectiveness of the model is validated, and the factors influencing rumor spreading are also explored by numerical simulation. In addition, a real social network dataset is used to further verify the validity of the proposed model. Simulation results show that the coupled networks more accurately reflect the rumor propagation process compared with the single-layer network and reveal the driving nature of internet water armies on the trend of rumor spreading. That provides theoretical support for the study of rumor dissemination and has important practical significance.</p>