Abstract: A stress calculation method has been established for a double layer shaft in special stratum. After some simplifications of the mechanical model，the problem has been broken down into three subproblems, and a Saint-Venant solution has been obtained by solving and adding up each subproblem. An example for certain double layer shaft has been presented, and the stress results have been compared with the single layer shaft of the same conditions. The fourth strength theory has been applied to study the security of the shafts, and the results show that, compared with the single layer shaft, the security for the inside lining of the double layer shaft is enhanced greatly, while the security of the outside lining is reduced. On the whole, the application of this double layer shaft is advantageous for the safety production of the mine，and the outside lining of this shaft is the weak zone that needs to be cured mainly.

Key words: special strata, double layer shaft, elastic analysis