Routing scheme of a kind of polymer five-port optical router is proposed, and it can optically route four channel wavelength data streams along certain definite-path in two-dimensional (2D) plane, owing to the resonance function of cross-coupling two-ring resonators with four different ring radii. Due to the large contrast between polymer core refractive index and the left/right cladding index, the four ring radii are as small as 14 μm, and the mode amplitude bending loss is as low as 10-4 dB/cm. Under the case of lights with different wavelengths inputting into different ports, the relationships between wavelength and routing path are derived. Simulation results on the device reveal that the insertion losses of each channel wavelength along each routing path are within the range of 0.03~0.62 dB, the maximum crosstalk between the on-port along each routing path and other off-ports is less than -39 dB, and the device footprint size is about 626 μm×495 μm. Compared with the previously reported silicon optical routers, this device possesses similar ring radius and similar device size. In addition, because of zero static power consumption, low crosstalk and insertion loss, simple processing technology and low cost, the proposed device shows potential applications in optical networks-on-chip (NoC).