A multi-intelligent telephone alarm monitor system based on pyroelectric infrared (PIR) detector is designed.Each detector which placed different monitor position can convey the detected signal to the centre of the system in a wireless method.After received the alarm information,the centre of the system can produce local sound of alarm and send the alarm information to remote place by telephone network.The principle and design method of the system are introduced.The process of realization and principle of the telephone dial-up are described.The results of test demonstrate that the system is convenient for use and agile for assembled and reliable for performance.