The influence of the nonlinearity of polysilicon silicon resistance on the overall circuit performance of signal chain was introduced, and the causes of the nonlinearity of polycrystalline silicon resistance were analyzed. Two nonlinear compensation design methods, substrate potential compensation and composite polysilicon compensation, were proposed. The performance of 12 bit D/A converter without compensation and with the new compensation method were compared by simulation and test. The results showed that the D/A converter with polycrystalline silicon resistance compensation and nonlinear compensation achieved better linearity.