In this paper,the time-spectrum formula of the second-order coherence degree g(2)(τ) of a two-mode He-Ne laser is derived,based on the quantum theory of the light.The periodicity, time-spectrum characteristics and photons anticorrelation effect of g(2>(τ)are studied. According to the analysis of g(2)(τ) tuning characteristics,we discussed the possible application of g(2)(τ) time-spectrum characteristics in two-mode laser field for laser linewidth measurement,and frequency and power stabilization of a two-mode laser.