The fidelity of quantum information for the multi-photon Jaynes-Cummings model with the frequency of the field varying with time in the sinusoidal form have been studied, taking advantage of computation，data processing，demonstration and comparison etc.The results show that the frequency parameters have obviously effects on the fidelity, with the increasing of the frequency parameters , with the detuning parameters increase, the fidelity of system，photon of field and atom also increase. And the frequency parameters of the field varying with time only effect the frequency of the curve，with the increasing of the frequency parameters, the frequency of the fidelity curve also increase