The invention relates to an online temperature measurement system for a wireless transmission mode of power equipment. The online temperature measurement system comprises a plurality of temperature measurement terminals, a transfer station, a backstage, and a plurality of client sides, wherein each temperature measurement terminal consists of a power supply, a single chip computer and a wireless emission module; the transfer station comprises a wireless receiving module and a power supply module, and the power supply module supplies power to the wireless receiving module; the backstage consists of a communication conversion module and a computer, wherein the communication conversion module converts 485 communication data into USB (Universal Serial Bus) data, an input end of the communication conversion module is connected with the wireless receiving module through a 485 cable, an output end of the communication conversion module is connected with the computer through a data line, a TCP/IP (Transmission Control Protocol/Internet Protocol) communication protocol, a VB (Visual Basic) communication module, a MYSQL database, a TOMACAT server and a JRE (Java Runtime Environment) running environment are installed on the computer; each client side is a computer, and all client sides are connected with the backstage through a network. Data can be automatically sent through circulating timing and a wireless manner, the power consumption is reduced, and the reliability is enhanced.