The temperature sensitivity is the key factor to influence the performance of optical biosensor based on waveguide microring. According the resonant equation of the waveguide microring, the mechanism inducing the temperature sensitivity is analyzed. The sandwich polymer substrate of SU8-NOA61-SU8 is employed to replace the conventional silicon substrate. The thermo- optic effect of the waveguide is counteracted by the thermoexpansion effect of the sandwich polymer substrate, resulting in the temperature insensitivity of the all polymer waveguide microring biosensor. The optimized thicknesses of the sandwich substrate for the temperature insensitive microring sensor are obtained by the design with ANSYS software. The films of SU8 and NOA61 are prepared with the spin coating technique. The controllable thickness precisions of SU8 and NOA61 films are 0.07μm@20r/min and 0.34μm@20r/min, respectively. The temperature sensitivity and the detection limit of the polymer waveguide microring biosensor with the sandwich polymer substrate are as same as the performance of the one on the silicon substrate with a temperature controller.