To overcome disadvantages of low transmission efficiency and high dependence on the incident angle for the transmitting type polarization beam splitter (PBS), a highly efficient PBS based on a two-dimensional photonic crystal slab is proposed, which consists of a honeycomb lattice of GaAs cylinders in air. The PBS has a normal refraction for TE polarization and a negative refraction for the other polarization (TM polarization) so that it can separate these two polarization beams totally in space. Anti-reflection layers (ARLs) at the surfaces of the photonic crystal slab are introduced and relevant parameters are optimized to improve the transmission efficiency. Two-dimensional finite difference time domain (FDTD) simulation results show that, in a wide angle range (about 20°), in a normalized circular frequency range of ω=0.20~0.23×2πc/a, the transmission intensity can reach over 98% for both TE and TM polarization.