The invention relates to a device for monitoring the pain state of a patient and a method thereof, the method comprises the steps of collecting patient odynolysis records of a patient from the clinical end in the wired or the wireless way, transmitting to the remote end via a transmission interface in the real-time or the non-real time way for data analysis and treatment and further carrying out analysis and feedback against treatment course feedback information of each user, the device comprises a patient PCA, a computer monitoring module, a network monitoring module and a network monitoring module database, and the device can further comprise a portable device and a PCA bluetooth wireless transmission module thereof. Therefore, clinical staff can integrate PCA information containing drug consumption and the pain state, and feed back the pain state of the patient in a real-time manner by leading the patient to visit the remote monitoring device, and has the characteristics of high postoperative service quality, complete medical records, low cost and capability of providing the basis for leading medical instrument manufactures to monitor market resource planning and assisting logistics and market development of the medical instrument manufactures.