Considering the significant value of the compression of the light beam for all optic networks and future integrated photonic/optical circuit, a beam compressor with two-stage compressions based on the efficient coupling between photonic crystal waveguides and nanowire waveguide is proposed. The first stage compression relies on the coupling between W1 and W5 photonic crystal waveguides. A nanowire waveguide with a width of 0.1 μm and a length of 3.06 μm is introduced to realize the second stage compression. The parameter of the rod located between the W1 photonic crystal waveguide and nanowire waveguide is optimized. When the radius of the rodis 0.04 μm, transmission efficiency and full-width at half-maximum (FWHM) of the output beam of the beam compressor are 93.4% and 0.148 μm, respectively. The compression ratio reaches to 16.08.