Abstract: In order to make up for the shortage in mining subsidence prediction calculation methods of existing random shape working face，and more accurately predict the value of surface movement and deformation caused by coal mining，the working face is divided into several trapezoids according to corners based on the theory of probability integral method.The variable step-size Simpson double integral method is adopted to conduct the integration in every trapezoidal region according to the prediction formula，and deal with the effects which were produced by every trapezoidal unit to realize the subsidence prediction calculation of random shape working face through superposition method.In addition，through the study of inflection point displacement effect on the working face position，the solution method for actually calculating angular coordinate at boundary of the random shape working face is discussed.On this basis，the mining subsidence prediction program is designed and developed，realizing prediction of surface movement and distortion，analysis of prediction results and visual output.The actual mine working faces in a mining area was taken as a case to verify the calculation method and prediction program.The results showed that the program design is reasonable，and the prediction result is accurate and reliable，and accords with the fact.It can meet the needs for a wide range of subsidence prediction and provide the necessary technical support for “under three” coal mining and land reclamation planning.

Key words: Random shape working face, Mining subsidence, Probability integral method, Movement and deformation, Variable step-size Simpson-method, Inflection point displacement