The large-separation dual-peak filtering characteristics of phase-shifted long-period fiber gratings (PS-LPFG) with film coatings are studied. When an LPFG is designed to work at the phase-matching turning point (PMTP), the coupling between core mode and a higher-order cladding mode produces a single resonant peak whose bandwidth reaches 288 nm and above. The introduction of a phase-shift into the center of this LPFG gives rise to two band-rejection peaks locating at the two sides of the central wavelength. The separation between these two peaks reaches 388 nm which is much larger than that of the PS-LPFG based on the coupling between core mode and a lower-order cladding mode. When the LPFG is devised uniformly by introducing M (M>1) π phase shifts, the separation increases with the increase of M. The loss at central wavelength is constant at zero when M is odd, whereas the loss at central wavelength decreases with the increase of M when M is even. The increase of film thickness and refractive index causes the two peaks to shift towards short wavelength and increases the separations. Furthermore, the increment of grating length changes the peak loss of dual peaks and decreases the separation.