Introduces the screw press press than in basic theory research, the basic model, and theory of crushing chamber than calculation related to squeeze free volume calculation, pressing and practical squeezing ratio calculation and squeezing squeezing coefficient than related research present situation of the study on five aspects, has been clear about the necessity of squeezing than the precise model is set up.palm oil millﾧ,Tung is the specialty of industrial woody oil species, cultivation has a long history and wide range of USES, the son duong district of shaanxi province is one of the county, tung production base in China.By Shanxi Province fanshi county agricultural machinery plants the development and production of double helix walnuts at low temperature oil mill, after many test, obtained very satisfactory squeezing effect, will be put on the market recently.Walnut meat is the highest woody plant oil crop, generally in more than 60%.Due to high oil content, so a lot of oil press susceptible to "crash" phenomenon in the process of pressing to normal squeezing, the solution is squeezed the walnutsbucket elevatorﾧ，For a small seed of tung tree squeezing are vegetable oil in medium and small trial run, there is currently no more perfect squeezing domestic technology.Small seed of tung tree (aka jatropha) belongs to the high oil content plant, its seed kernel oil content as high as 55% - 65%, black seed, toxic, shaped like a castor seed, seed kernel white appearance than flowers Raw seed kernel slightly longer, slightly flat.Squeezing method similar to castor, experiment found that the oil without heating steaming and frying.Currently adopted by the medium test line type oil press for SYZX12 double spiral oil press, adopts two crushing, high oil production rate, slag cakes in the residual oil in 5 ~ 6%.