Abstract: Despite efforts attempting to increase the protein extraction rate from soybeans in dried soybean sheet production,the recovery rate remains less than 50%.This article reviews the factors affecting the yield,and presents the results from our experimentation targeted at the soybean-milling and slurry-filtration of the protein extraction prior to sheet formation.The traditional sand and colloid grinder milling methods,ratio of soybeans to water,milling time and particle size were examined.The orthogonal experimentalresults showed that a multiple stage separation should be used for the process.A maximized protein recovery could be obtained by a two-stage filtration:firstly,using the sand milling with a water/soybean ratio of 4.5/1to grind the soybeansfollowed by filtration through a 80 mesh silk cloth;then,applying the colloid grinder with a water/milled slurry ratio of 3.5/1followed by filtration through a 100 mesh silk cloth to collect the soy milk for sheet-making.The yield of soluble matters and quality of soy milk were significantly increased resulting in 56.3%increase on the dried soybean sheets.