SF6 is the most commonly used insulating gas in gas insulated equipment. It is important to know the composition and content of decomposition components to timely and accurately judge the insulation and aging of equipment. Therefore， based on Raman spectroscopy technology， a set of Raman detection system is designed in this paper， which is composed of gas measurement module， function module， embedded control module， computer module and others， with the functions of temperature and pressure control， signal enhancement， mixed gas detection and analysis. The experiment of Raman system is carried out with SF6 and its decomposed components mixture. The characteristic peaks of SF6， SO2F2， SO2， CO2， CO， and H2S are 776 cm-1， 861 cm-1， 1 138 cm-1 and 1 378 cm-1， 1 269 cm-1， 2 185 cm-1， 2 600 cm-1 respectively， which are consistent with the NIST standard values. It is proved that the Raman spectrum detection system is feasible and provides a good basis for the detection of SF6 decomposition components， which is of great significance to ensure the safe and stable operation of power grid.