A new algorithm for P-wave reverse time migration (RTM) in a fracture-induced TTI double-porosity medium is proposed in this paper, by combining RTM with the method of P-and S-wave field separation in high-order staggered grid finitedifference scheme. Simulation results show that for the fracture-induced TTI double-porosity medium the conventional migration with a background velocity without fractures would cause the imaging position to be under the true interface. To study the influence of fracture parameters, the phase velocity formulae are derived from Christoffel equations, and the effects of fracture angles and density are analyzed. In the 2D case, the imaging position gets closer to the real interface along with increasing fracture dip angles, while a bigger fracture density can cause much more deviation.