In this paper, a fractional Ricatti expansion method is proposed to solve a nonlinear time fractional Fitzhugh-Nagumo equation in the frame of conformable derivatives, we also apply it to the nonlinear fractional Newell-Whitehead -Segel and Zeldovich equations which are an particular case of fractional Fitzhugh-Nagumo equation. In order to illustrate the accuracy and validity of this method, some numerical solution are given.