With the rapid development of nuclear-magnetic-resonance gyroscope( NMRG) tychnology,high precision NMRG demands for high performance vapor cell. The transverse relaxation time( T_2) of Xe nucleon,which is contained in the vapor cell,is one of the important parameters for vapor cell performance. The commonly used method is the free induction decay( FID) method. When T_2 is short,the T_2can't be tested well as the signal is easy disturbed by the environment. Based on the theory of the nuclear magnetic resona...