The present invention relates to a pressure adjusting device for a device of pulverizing and extracting agricultural products. The pressure adjusting device comprises: a fixing ring coupled and installed on an end portion of a feeding outlet of an extrusion pipe unit, through which the agricultural products are extruded, transported, and discharged, and fixatedly installed on a flange provided on an end portion of a discharge unit of the feeding outlet； and a pressure adjusting plate disposed on the fixing ring, having an elastic circumferential portion, and selectively opening the feeding outlet while sealing the end portion of the discharge unit. Accordingly, the pressure for extruding and transporting the agricultural products is regulated over an inlet of the extruding pipe unit and an inner space of the discharge unit until the supply of the agricultural products fed through an initial feeding hole reaches a predetermined amount. Therefore, it is possible to enhance efficiency of extrusion and transportation when the agricultural products pass through a feeding unit and the discharge unit during a process, in which the agricultural products fed through the initial feeding hole reaches the predetermined amount. As the pressure adjusting plate and an opening/closing valve for selectively opening and closing a discharge guidance hole formed in the center of the pressure adjusting plate are applied, only solid agricultural products are discharged to the discharge guidance hole through the opening of the opening/closing valve when a relatively low extrusion pressure is applied. When a relatively large extrusion pressure is applied, the opening/closing valve is opened, and the pressure adjusting plate is moved, such that the solid agricultural products pass through the discharge guidance pipe of the pressure adjusting plate and an outer discharge guidance slope on a separated circumferential portion of the pressure adjusting plate, and are discharged to the outside t
