In this paper,serum Raman spectroscopy was used to investi gate the causes and mechanisms of the association between the incidence of post-traumatic stress di sorder (PTSD) and the length of exposure time in the trauma environment.In this experiment, 28rat serum samples were tested with prolonged traumatic environment exposure time and 27rat serum samples for non-prolonged traumatic environment exposure time.The tentative assignments of the characteristic peaks in the serum Raman spectra of the tested rats indicate that certain biomol ecules between the groups have certain differences.Principal component analysis is used to extract features to reduce the dimension of high-dimensional spectra to enhance the rate of discriminant model s.The extracted features were classified with BPNN,ELM and SVM.The SVM algorithm established p attern recognition model with the Linear kernel,Polynomial kernel and RBF kernel respectively.Th e PCA-RBF-SVM obtained thebest results with an accuracy rateof 94.5%.Theresult s of this study indicate that there is a significant difference in the serum Raman spectra with different exposure time in traumatic environments.The exposure time can change the chemical or mol ecular substances,whichmay leadto changes in theincidenceof PTSD.