Based on the nonlinear fractional Schrodinger equation (NLFSE), the optical modes in nonlinear PT symmetric waveguides and their stability are studied. Firstly, the optical modes in PT symmetric waveguides with fractional diffraction effects are given by using the square operator method. On this basis, the effects of fractional diffraction effect and non-Hermitian effect on the stability of these optical modes are studied by linear stability analysis method, andthe dynamics of linear stable and unstable optical modes are numerically simulated by using the stepwise Fourier method. The results show that there are ground states, first, second and third excited state optical modes in the fractional diffraction effect nonlinear PT symmetric system.