Abstract: It is crucial to directly confirm the presence of water by detecting water ice and its content in the lunar polar region in situ. Spectroscopy and mass spectrometry are both important tools for identifying and quantifying material composition. They can complement each other to achieve comprehensive detection of water ice, volatile content, and H isotope abundance in the lunar polar region. The paper introduces the spectroscopy and mass spectrometry technique with Luna 25, Luna 27 and Viper as examples of typical in-situ detection applications. It includes the detection mechanism, operating mode and instrument functions, performance and applications. In last, we provided a brief introduction to the upcoming application of the “Chang’e-7” lunar polar region water molecule analyzer. This instrument comprises a laser absorption spectrometer, which is responsible for the in-situ analysis of H₂O and HDO, and a time-of-flight mass spectrometer that enables the analysis of gas molecules with mass numbers < 200 amu, such as H₂O and CH₄. The scheme can support in-situ analysis of water ice for lunar south pole landing missions.