Objective To study the application of the trinity model and trinity forecasting method in predicting the incidence trend of pulmonary tuberculosis (PTB). Methods By applying the monthly PTB incidence data in Zhejiang Province from 2011 to 2021, a prediction model was constructed based on the trinity model and trinity forecasting method. Predictive performance of the model was evaluated. Results The mean relative prediction errors of model 1 and model 2 based on trinity model and trinity forecasting method were 7.94% and 8.43%, respectively. The mean relative prediction error obtained by adopting autoregressive integrated moving average (ARIMA) model was 8.87%, and the above mean relative prediction error were all in the range of 7.9%-8.9%, which presented an excellent performance of the forecasting model. Conclusion The trinity model is an excellent time series forecasting model, and the trinity forecasting method is an excellent time series forecasting method, with high application value.