Civil aircraft is equipped with fuel temperature indicating system to continuously monitor the fuel temperature in the fuel tank to avoid fuel freezing and ensure that the fuel supplied to the engine / APU meets the temperature requirements. This paper introduces the composition and design points of the fuel temperature indication system for civil aircraft, and takes a single-aisle civil airliner as an example to analyze the fuel temperature alarm setting considerations, alarm value setting, alarm level and the pilot’s operation. It is proposed that the fuel temperature sensor installation location should consider the aircraft fuel pump installation location, fuel consumption sequence and fuel consumption law, the fuel temperature alarm should consider the aircraft system design configuration, and set the high temperature alarm for the configuration that the fuel temperature in the fuel tank will increase during flight, and the fuel low temperature alarm should be set in addition to the special configuration. The low fuel temperature alarm threshold should take into account the fuel freezing point and the inlet fuel temperature required for the normal operation of the engine / APU to ensure that the fuel temperature in the fuel tank meets the requirements. After the low fuel temperature alarm is triggered, the pilot should operate the aircraft according to the fuel type and freezing point.