Controllable printing of microstructure with specific composition and structure distribution is the key technology to miniaturize and integrate nonlinear optical devices. Spatial and geometry controls of second order nonlinear optical properties at the micrometer scale have been achieved in soda lime glass (SLG) using microthermal poling with nickel mesh as anodes and SLG as cover glass. Microstructured second harmonic generation (SHG) can be correlated to the dielectric barrier discharge (DBD) of a poling sandwich among an SLG sample, a nickel mesh, and a SLG cover. Experimental results show that the DBD induces an internal electric field with a geometrical intensity distribution in the SLG sample and cover. Furthermore, energy dispersive X-ray spectroscopy and Raman spectroscopy reveal that microstructured SHG patterns are attributed to the internal electric field induced by Na ⁺ redistribution and structural rearrangement of SLG. Microthermal poling can be used to fabricate nonlinear optical components.