The proposal of multi-stage interlaced structure provided a new idea for the design of multi-channel sub-wavelength arrayed waveguide grating (AW G) with high resolution. An optimal design method for two -stage interlaced AW Gs is described and verified with a 135-channel interleaved AW Gs comprised of a 5-channel primary AW G with 0.5nm of resolution and five 27-channel second-stage AWGs each with 2.5nm of resolution with sub-wavelength waveguide. The bandwidth of the whole system is 65nm centered at 1950nm. Compared with conventional multi-channelschemes, it not only greatly reduces the process requirements and provides greater tolerance, but also simplifies the process of layout design. The AWGs demonstrated is proved be suitable for the development of 2μm optical communication.