The invention relates to a positive end expiratory pressure valve pressure control device which comprises an exhalation valve 2, a proportional valve installation base 4, a flow proportional valve 5 and a current-limiting capillary copper pipe 1, wherein one end of the proportional valve installation base 4 is connected with one end of the exhalation valve 2, the flow proportional valve 5 is arranged on the proportional valve installation base 4, and the current-limiting capillary copper pipe 1 is connected at the other end of the exhalation valve 2. The positive end expiratory pressure valve pressure control device is characterized in that the pressure control device is simple in design, only one current-limiting capillary copper pipe 1 is additionally arranged in the traditional structure, cost of the current-limiting capillary copper pipe 1 can be ignored, fixed low flow and pressure input are supplied in a positive end expiratory pressure (PEEP) cavity of the exhalation valve 2, and the flow proportional valve 5 is used for controlling the caliber of an exhaust port located in the PEEP cavity of the exhalation valve 2 so as to change the PEEP. Matching requirements on the flow proportional valve 5 and hardware platforms is correspondingly reduced, the exhaust end of the flow proportional valve 5 is directly connected with the air, fast response can be carried out along with valve adjustment, the delay time is shortened, and reliability of breathing machines is improved.