The band structures of triangular hole lattice photonic crystal are studied via plane wave expansion method, with radiation loss considered. The spectrum transmission characters of the designed structure are investigated through simulation of finite difference time-domain method (FDTD) for hexagonal ring resonant, and the parameters of lattice period and radius of the lattice hole are optimized. The drop efficiency rate of 98.8% and FWHM of 32.9 nm are reached through optimization of the designing in C-band. The samples are tentative fabricated through photolithography and reactive ion etching and the parameters are given. The transmission spectrum is measured and the reasons of differences from the theoretical result are analyzed. The schemes of slab based on ring resonant holes show a more stable character than the rod ones, and have potential future for filters, WDM devices and micro gyroscope.