In order to meet the special demand of protection work, a new structure type of composite shell was put forward. The composite shell, which composed of spatial latticed shell structure and steel-concrete composite slab and the former is covered by the later, is a half-bred structure. With all merits of latticed shell and composite slab, the composite shell's structural performance is very excellent. To instruct structure design and test, the nonlinear property of new type of composite latticed shell, which based on spatial integral action is analyzed overall by FEM software ANSYS. The result of analyses shows that the new type of composite shell is a very excellent form of protection structure because of its prominent mechanical property.