According to the requirement for temperature and humidity measurement in thermal equilibrium experiment of a freight spacecraft, a distributed measuring system based on controller area network(CAN) bus and SHT15 intelligent temperature and humidity sensor was designed and constructed. The collected data of measurement modules were transferred to the slave computer(SC) through concentrator, then sent to the personal computer (PC). Data calibration, display and storage were realized. The design concept and flow chart of software in the system were provided. Experiments of vacuum storage and calibration were conducted. The results show that the system has high reliability and accuracy. Measurement errors of relative humidity are less than 2%. Furthermore, the system is convenient to use and increase nodes. The system has been used in actual measurement.