Coherent structures of two-dimensional supersonic turbulent mixing layer with engineering background are investigated by using the method of Large Eddy Simulation (LES). Chaos characteristics of evolution status are obtained by the non-linear time series analysis of pseudo-phase portrait, Lyapunov exponent and correlation dimension. The results show that the pseudo-phase portrait of pressure can denote the stability of mixing layer. The distribution of correlation dimensions can be used to measure the evolution status of mixing layer quantificationally, and the distribution of maximal Lyapunov exponents can be used to validate the measure results above. In corresponding experiments for mixing layer, the universality of studies on evolution status of mixing layer by the method of non-linear time series analysis is testified.