The oil content of tung oil seeds varies with the place of origin, with an average of over 35%, and the oil content of seed kernel is about 60%. Generally, mature tung oil seeds are collected in autumn, and the peel and seed coat are removed for oil extraction. The ancient method of pressing oil with a wooden wedge is manual operation, which is labor-intensive, and the oil yield of tung oil is low (generally 22-25%, up to 30%). Bran cake (meal) As high as15%), the oil loss is high. In modern times, mechanical oil extraction or solvent leaching has been used. The hydraulic oil press or screw oil press is used to extract oil. The oil yield of tung oil in hydraulic oil press is 25 ~ 30%, and the residual oil rate of bran cake is 6 ~10%. The cakes and bran cakes are grooved and unloaded. The residual oil rate of bran cake is 5-8%. All the processes from feeding, shelling, crushing, steaming, pressing to processing into oil are controlled by mechanical operation and instruments. When extracting with solvent, the bran cake pressed with tung oil is used as raw material because of its rich oil content and long extraction time. The wood-pressed bran cake can extract 7-10% of oil. The mechanical pressed bran cake can leach 5-8% of oil, and the minimum residual oil rate of the mechanical pressed bran cake is 4%. The residual oil rate of the bran cake can be reduced to1%by solvent leaching.