A temperature and pressure measuring system which uses ultrasonic signals for communication is designed. The system uses strong penetrate characteristic of ultrasonic signal in rigid body medium. Through two kinds of frequency signals of 40 k Hz and 1 MHz representing different data bits to complete transfer of information.The system takes STM32F103 as controller

and through peripheral circuit to drive ultrasonic transducer to excite ultrasonic wave

so as to cause vibration of external transducer to finish commnication. Error code processing algorithm and system hardware constitution are introduced. By testing

system error of temperature measuremet is less than 0. 1 ℃

and error of pressure measurement is less than 0. 1 % FS.