The identification of stability about flame combustion plays a vital role in the industrial production of plants. Paper integrates the phase information into identification system extracted by higher order spectral, and stresses on identifying the stability of flame combustion with the application of the Mahalanobis Distance, combined with the other two characteristic quantities: the flame intensity variance and flicker frequency. The Mahalanobis Distance can overcome the interference correlation of the flame characteristic quantities and the impact of different dimensions, so the identification rate reaches to 93%, which effectively verifies the correctness of the Mahalanobis Distance.