Abstract: In order to obtain the real-time spectrum recovery of spectrum information such as battlefield laser, atmospheric pollutants gases, poisonous gas, etc. the real-time spectrum acquisition and analysis system based on FPGA was designed. The spectral information was abtained by using a Michelson interferometer and HgCdTe detector, and the collected date was transmitted to FPGA. Using hardware language Verilog HDL on the chip of Xilinx FPGA, the system achieved real-time processing of the spectrum data from interference pattern based on FFT. The simulation result indicates that the spectrum distribution information calculated by 1 024-point radix 2-FFT with FPGA is the same as the theoretical calculation result of Matlab, which can meet the requirement for real-time spectral detection.