The modeling method of the temperature distribution in glass greenhouse with forced-air heater based on the CFD technique was proposed. The flow regime proved to be turbulent and it was modeled by using the standard k-ε turbulence model, and the non-gray DO model of radiation model was also applied. The numerical solution was made by applying a finite volume discretization code with the pressure implicit with splitting of operators (PISO) algorithm. The temperature data of the key position were collected in a three-span Venlo glasshouse. By using the root mean squares error (RMSE) algorithm, the error between simulated value in Fluent and measured value was simulated and analyzed. The results indicate that the CFD-based model can provide reliable estimation of the temperature distribution in the greenhouse during the forced-air heater working.