In the theoretic research of the superfluorescent source (SFS), the classic methods have some drawbacks such as high complexity and low stability. Comparatively, due to low complexity, good stability and quick convergence, the Giles model is widely applied into the theoretic research of the erbium-doped fiber amplifiers (EDFAs). Considering the similar structure of them, the Giles model is first introduced into the research of the SFS. Then, by using the four/five-order Runge-Kutta method, the curves of output power of the SFS with the single-pass forward configuration are obtained with the changes of the length of EDF, the density of Er3+ ion and the pump power. And the numerical results shows that, by using Giles model, not only the characteristics of output power of the SFS is figured out accurately, but the complexity of the simulation algorithm is reduced greatly, which improves the practicability of the theoretic research method of the SFS.