Wireless modem redundant backup circuit

The utility model provides a redundant backup circuit of a wireless modem. The redundant backup circuit comprises a main modem, a backup modem, a CPU (Central Processing Unit), a communication interface change-over switch, a USIM (Universal Subscriber Identity Module) interface change-over switch, a USIM card, an antenna interface change-over switch, an antenna and a power supply switch. According to the utility model, redundant backup is carried out on the main modem, when the main modem fails, the main modem is switched to the backup modem, the connection between the equipment and the background network management is realized through the backup modem, and the main modem and the backup modem share the power supply, the USIM card and the transmission antenna, so that the reliability of an equipment transmission link is improved under the condition that the system power consumption and the engineering construction and maintenance difficulty are not increased. 本实用新型提供一种无线modem冗余备份电路，包括：主用modem、备份modem、CPU单元、通信接