The double-cave is the symmetrical caves of the most historical and artistic value in Yunang Grottoes. Take typical double-cave of 9_th -10_th to build finite difference model, utilize the measured mechanical parameters for numerical analysis to study stress and deformation of chamber sorrouding rock under static condition. Results show that the double-cave endure pressure stress and local shear stress: the large pressure stress is in the bottom of partition wall between caves and between chambers as well as the upper of column for 1.20-1.57 MPa, the large shear stress is in the upper of partition and the top of column for 0.1-0.3 MPa. No plastic strain shows that the double-cave structure is unbroken under current condition. The displacement-vectoer nephogram of Slice(y=20m) shows the maximum settlement on the top of the main chamber for 1.1mm, the groud of the front and the main chamber have relative uplift, it should pay attention to.