Abstract: In order to save the rare iceland and increase the shear difference,a new type of parallel beam splitter,combined iceland with glass,was designed.In the prism,there is a piece of optical glass between two parts of iceland with air gap or glue among them.At the premise of good extinction ratio and high transmittance,and the saving of the iceland,it can be indicated by the theory and experiment that the shear difference of the prism increases 3 times than that of the general parallel beam splitter.