The invention discloses a system and method for promoting brands by converging terminal clients through wechat communities. The system comprises an analyzing unit, a collecting unit, a building unit, an activity unit, a correction unit and a promoting unit; the analyzing unit is used for making the standards of the terminal clients joining the wechat communities; the collecting unit is used for collecting client information of the terminal clients; the building unit is used for building the wechat communities according to the client information; the activity unit is used for organizing community activities; the correction unit is used for correcting the community activities and the compositions of the wechat communities; and the prompting unit is used for promoting activities to the terminal clients in the wechat communities and finishing promoting the brands. According to the system and the method provided by the invention, through building a series of retail terminal client wechat communities based on wechat communities and carrying out standard management to the wechat communities by using a system management mode, the retail terminal clients are converged integrally; the retail terminal clients are converted into the loyal clients of the brands; and the attentions to the cigarette brands are amplified.