This invention discloses a patient pain monitoring system and a portable power output device, wherein the patient pain monitoring system comprises a server, a transfusion pump and the portable power output device. The server has a patient database. The transfusion pump outputs an anesthetic to a patient and is connected to a power transmission module. The portable power output device provides power to the transfusion pump. When a medicine request button is pressed, a processing unit can obtain the voltage value corresponding to medicine administration data. Afterwards, power from the power supply module is transmitted to a power input unit, and the processing unit and a voltage conversion unit are used to convert the power and output a predetermined voltage for output to the transfusion pump to drive the transfusion pump to inject the anesthetic into the patient. Finally, the information transmission module outputs the medicine administration data to the patient database for analysis by the server.
