Abstract: The Galileo Search and Rescue system is a part of the Global Satellite Search and Rescue System(COSPAS-SARSAT),which is carried on the Galileo navigation constellation.Using the Galileo Search and Rescue system,the distress signal can be localized and then rescue activity can be executed.The signal to noise ratio of satellite transmitted signal by is very low,so it is extremely important for the operation of search and rescue system that whether it is able to detect signal under the condition of low signal to noise ratio.In order to solve this problem,a frequency domain detection method based on FFT operation was presented.The theoretical analysis and simulation verification show that the satellite signal can be effectively detected under low signal to noise ratio using this method.