The GeSi/Si superlattices structure is grown on the n +/n - Si wafer by MBE method. The detector and the Si rib waveguides are formed by reactive ion etching. The integration of Si waveguide and GeSi/Si superlattices PIN photodetector is fabricated throuth the suitable process. The minimum dark current of PIN detector is 0.8 μA and the maximum photocurrent is 2.7 μA at 5 V reverse bias. The maximum overall quantum efficiency of photodetector of 14.2% was obtained. The working wavelenth λ=1.3 μm.