The shell capacitive electronic manometer with internal trigger has some shortcomings, such as error trigger and no trigger, complicated plug line communication and communication socket easy to be worn. According to the shortcomings, the shell capacitive manometer and infrared communication for capacitive manometer is designed. The high strength transparent shield window and photoelectric trigger circuit are designed to ensure the manometer with light energy trigger to collect and storage pressure signals in a testing field. And the electromagnetic interference affected to the testing circuit is shielded. The infrared communication interface is designed. The normal communication between the manometer and the host computer is realized. Test experiments show that the improved manometer can operate reliably.