In order to meet the requirements of bridge monitoring

wireless transmission of the collected data is realized

and data wireless acquisition and transmission system is designed. The STM microprocessor and the vibrating wire sensor are used as the core components to monitor and analyze the bridge strain. Working principle of vibrating wire sensor is analyzed

and two kinds of traditional excitation principle are compared and analyzed.The advantages and disadvantages of two kinds of excitation modes are discussed

and improved method of low voltage frequency swept excitation principle is put forward

and excitation circuit is designed and optimized.Wireless sensor networks based on NRF905 are designed and wireless transmission and reception are achieved.The experimental results show that presion of measurement based on improved excitation principle is less than0. 1 %

the system is stable and the wireless transmission function meets requirements of bridge monitoring.