The formula of electron energy loss spectroscopy of metal nanostructures was deduced by Green function. Several typical structural systems were simulated by finite difference time-domain method. The regulating effects of the distance between the moving charge and the structure, and the liquid crystal environment on the electron energy loss spectrum were numerical simulated. The simulation results show that the electron energy loss spectral peak decreases when the distance between electron and nanostructure is increased. When the liquid crystal material or isotropic substrate material is added, the peak value of electron energy loss spectrum is redshift，but with the tilt angle of the optical axis changes, the modulation effect is limited. The surface plasmon resonance on metal nanoparticles can be studied by calculating the electron energy loss spectrum, which provides a basis theoretical for the design of highly complex plasmonic nanostructures.