The bending characteristics of dual-hole polarization maintaining photonic crystal fiber (PM-PCF) are demonstrated in this paper. The modal interference is induced by the LP₀₁mode and LP₁₁mode propagating in a single PM-PCF with the same polarization direction. Simulation results demonstrate that the bending radius induces the phase difference between LP₀₁mode and LP₁₁mode, which leads to the change of light interference intensity on the fiber output facet. The relationship between bending radius and normalized interference intensity with three different bending angles is discussed, where the bending angle is defined as the angle between hole axis and the x axis. The bending sensitivity is obtained to be about -188.78/m around the bending radius of 1.5 cm with the bending angle of 90°. The bending characteristics can contribute for online bending detection in widespread areas.