Tritium is very important fusion materials, it has been broad applied both in military area and in civil area. It is very important to study the depth profile and composition of tritium in materials. This thesis establishes the whole simulation method for tritium b-ray induced X-ray spectrometry technique and researches the algorithm of X-ray spectra simulation, and the X-ray spectrum and the depth and composition of tritium based on simulation has been investigated to expose their relationships. The results show that there is a corresponding relationship between depth profile and X-ray spectra, and the results lay a foundation for further research on inverse problem.