In our work, polymer-based micro lens arrays with spacers were innovativly fabricated by low cost wafer-level glass-silicon molds. The upper glass mold was prepared by a well-controlled hot forming process (HFP) combined with a chemical foaming process (CFP). The under silicon mold was formed by an etching process. Before dispensing UV-curable glue between the two concave molds, the contact surface should be coated with an anti-stick layer. After UV curing and de-molding, the micro lens arrays were successfully fabricated. The lenses were inspected by an atomic force microscope(AFM), a white light interferometer and a beam analyzer. The results demonstrate the excellent quality of surface roughness and optical characteristics. This study indicates the potential of this novel molding process for industrial production.