Multi-level combined forecast thinking and scenario analysis are combined, and a scenario-based control
combination forecasting model with non-negative variable weight is built. The model has the characteristic which combines
single forecast models and scenarios. And the adaptability and the controllability of the model are improved. Taking
economic growth of S city as the background for analysis, planning out the four alternative scenarios, data from the 1979 to
2010 fit four kinds of single-prediction model and forecast economic conditions from 2011 to 2015. Thus a scenario-based
non-controllable negative variable weight combination forecasting model of the city S is constructed, and the actual situation
of economic growth is analyzed.