The invention discloses a temperature measuring system with high precision and strong interference resistance and a method thereof, and the temperature measuring system consists of temperature sensors and a controlling computer, and is characterized in that the temperature sensors are a plurality of temperature sensors that are respectively arranged on each part of a large-scale astronomical telescope, outputs of the temperature sensors are respectively connected with each temperature survey meter, an analog signal amplifying circuit, an analog-to-digital converter, a data acquisition system,a temperature displaying device and a serial communication circuit are respectively arranged inside each temperature survey meter, which is remotely connected with the controlling computer through the serial communication circuit and the Ethernet. The temperature measuring system adopts the high-precision temperature sensors and temperature survey meters as well as the method that combines hardware with software, thus improving the interference resistant capacity of the system, eliminating power frequency interference and random interference and satisfying the requirement of remote data transmission; simultaneously the temperature measuring system utilizes the Ethernet technique for sampling multi-way temperature data, thus recording and storing measured temperature data in real time and providing reliable foundation for improving astronomical seeing in astronomical observation.