The invention, which relates to the technical field of cut tobacco drying process moisture control, discloses a cut tobacco drying process moisture prediction control method and system based on a recurrent neural network. The method comprises the steps: step A, collecting related data of a cut tobacco drying process; step B, automatically identifying acquired trademark information to obtain control parameters; step C, judging the related data, and establishing a nonlinear prediction control model; step D, converting a nonlinear prediction model into a nonlinear prediction control model based on a recurrent neural network, and updating the weight of the recurrent neural network to obtain an outlet moisture content prediction value; and step E, constructing a performance index J, and acquiring an optimal moisture removal air door opening degree of the performance index J. According to the method, the nonlinear prediction control model is improved, the neural network training speed and stability are improved, and the stability of the outlet moisture content is improved.