In order to study the observation of postoperative vital sign data of critically ill patients, this paper developed a set of vital sign data acquisition system based on intelligence and realized the design of vital sign data acquisition system APP based on Android Studio programming software, which was used to realize the information collection of vital sign data of patients. PDA is connected with a vital sign measuring equipment through Bluetooth. The patient's wristband is scanned with PDA to read the patient's information, and then the measured vital sign data are obtained automatically by measuring APP. The initial alarm value is set to be greater than 1%, and it needs more than 60 and less than or equal to 120 RR interval data to judge apnea. Information collection of intelligent vital sign detection can not only save the time of nursing staff but also improve the nursing quality.