Wepresent a novel method for engineering ultra-flattened-dispersion photonic crystal fibers with uniform air holes by rotations of inner air-hole rings around the fiber core. By choosing suitable rotation angles of each inner ring, theoretical results show that normal, anomalous, and nearly zero ultra-flattened-dispersion fibers in wide spectra ranges of interest can be obtained alternatively. Moreover, in our dispersion sensitive analysis, these types of fibers are robust to variations from optimal design parameters. The method is suitable for the accurate adjustment of fiber dispersion within a small range, which would be valuable for the fabrication of ultra-flattened-dispersion fibers and also have potential applications in wide-band high-speed optical communication systems.