Based on the platform of lithium niobate on insulator， a periodically poled lithium niobate thin film waveguide structure was designed. By utilizing the excellent nonlinear properties of lithium niobate combined with flexible phase matching schemes， the influences of structural dispersion on the poling period were analyzed. In addition， the difference in effective refractive index of waveguide mode varied with temperature was employed. The bandwidth of frequency conversion is expanded effectively by changing the material temperature， achieving the double-frequency in the range of 1.5 μm to 1.6 μm. Finally a normalized conversion efficiency of 562% is obtained， which provides a theoretical basis for further research on parametric conversion of chip photonics.