Abstract: It is an important part of the space environmental situation awareness to forecast the solar energetic particle (SEP) events quantitatively. Generally, the high energy particles in most major SEP events originate in the front area of the shocks driven by the coronal mass ejection (CME) and are accelerated by a machamism of the diffusive shock acceleration (DSA). In this paper, an SEP forecast toolset is developed on the basis of three specified models, and the solar wind observation parameters of the satellite at the 1 AU and the CME observation parameters of the coronagraph. The parameters of a realistic SEP event is simulated and compared with the GOES spacecraft observations. It is shown that the simulated flux of the particles of more than 10 MeV fits the observation well, while the simulated flux of the particles of more than 100 MeV is a little higher than the observed result. Furthermore, we have conducted the ensemble numerical simulations over the particular event and investigated the effects of different CME speeds as well as the background solar wind temperatures at the inner boundary on the SEP events. The results show that the CME speed plays a very important role in determining the particle flux and the power spectrum, while the effect of the background solar wind temperature is negligible.