There have been quite a few research works on the topology optimization under stress constraints. However, most of them only treated two dimensional (2D) cases. In the present work, a new approach for topology optimization of three dimensional (3D) shell structures under stress constraints is presented. This approach is constructed by combining the Moving Morphable Void (MMV) approach with trimming technique-based Isogeometric analysis (IGA), where the shell geometry is described using Non-Uniform Rational B-Spline (NURBS) and a set of trimming curves. The proposed approach not only shares the same advantages of MMV approach for topology optimization (e.g., involving small number of design variables, linking with CAD system seamlessly, etc.), but also has the capability of providing high accuracy stress analysis results using much smaller number of degree of freedoms with the help of trimming surface analysis (TSA) technique. Several numerical examples are also presented to demonstrate the effectiveness and advantages of the proposed approach.