Abstract:The roof and side of fully-mechanized caving roadway are coal body or coal pillar which cause the stability problem extremely prominent. The fully-mechanized caving roadway of Nantun Colliery is set as the prototype,its surrounding rock stability problem is analyzed by numerical simulation with distinct element method and the variable and time series that describe system dynamic state are collected. The chaos and dynamic feature of the surrounding rock system are studied based on the power spectrum analysis,extraction of fractal dimension and calculation of maximum Lyapunov exponent. The deformation mechanic process of fully-mechanized caving surrounding rock is chaos dynamic process which is sensitive to initial factors;the pillar width and support condition have great effect on surrounding rock displacement,stress and damage area. The power spectrum has the feature of continuation,noise background and wide peak,the correlation dimension value is fraction and maximum Lyapunov exponent is generally greater than zero when the pillar width less than 3 m;the system would be in a chaos motion state at present. When the pillar width is 3–4 m and after bolt support,the wide peak feature of power spectrum vanished and the frequency spectrum is not profuse;the correlation dimension value is fraction but maximum Lyapunov exponent changes from positive to negative;system state changes from chaos motion to normal motion;this status is an inflection point of system dynamic state transformation. When the pillar width larger than 5 m,system will be in normal motion state. The reasonable pillar width is 3–5 m. The chaos dynamic feature of fully-mechanized caving roadway can be evaluated according to the application of power spectrum analysis and maximum Lyapunov exponent method.