Theoretical calculations via the transfer matrix method (TMM) are performed to investigate optical properties of one-dimensional semiconductor-organic photonic crystals (SOPC) with periodic conjugated polymer (3-octylthiophenes,P3OT)/AIN multilayer structure. The SOPC presents incomplete photonic band gap behavior in the UV region. P3OT/A1N multilayers with two pairs of 30nm-P3OT and 30nm-A1N layers exhibit a photonic band gap at a central wave- length of about 275nm,and the highest reflectivity reaches 98%. Furthermore,the band gaps are confirmed to be tunable by adjusting the lattice period and the filling fraction. As a consequence, the SOPC is important for achieving materials with an incomplete band gap in the UV region.