A new type of polydimethylsiloxane-based paper transparentizing agent was prepared via a combined method. The performance of the transparentizing agent was investigated systematically by adding and dipping, with use of the surface sizing device of a paper machine. Optimum performance was found at 30% concentration of the transparentizing agent and 30 to 45 °C of dipping temperature. Under the optimal conditions, the transparentizing t agent achieved a rapid penetration in the base paper and filled in the pores of the paper, to be further effectively adsorbed and retained on the fiber surface. The transparency of test paper reached as high as 76±0.97 %, which was 37±1.4% higher than that of the control. However, the addition of transparentizing agent reduced the mechanical strength of paper slightly. The as-prepared transparentizing agent was found to exhibit excellent application stability and biodegradability when applied in the paper machine，When used as plastic film, the transparent paper would lose its strength completely after eight weeks. The resulting transparent paper can be used to develop paper-based film and other related plant based transparent/ translucent paper, which has great potential in replacing plastic products and eliminating white pollution.