A new idea was put forward to the chaotic characteristics of deformation of mine shaft by means of phase space reconstruction of chaotic.Problems of space reconstruction of deformation value,correlation dimension determination,Lyapunov exponent calculation and stability were discussed.The result of the simulation experiment shows that the deformation system is a chaotic system,and affected by many factors;the biggest Lyapunov exponent may serve as the determinations standard of shaft deformation.The research can offer some help for the policy-making of the determination of stability in goaf.