A new dynamic passband filter enable to control the bandwidth using converging readout beam in photorefractive diffraction grating with high-efficiency is proposed and experimentally demonstrated. In this proposed scheme, the 3dB passband of a volume grating in crystal is theoretically predicted and the experimental results are obtained in consistent with our derivation that the bandwidth is controlled from 0.35nm to 3.3nm at the center wavelength of 670. 1nm.