BRepAlgoAPI_Fuse get wrong result

BRepAlgoAPI_Fuse get wrong result when do operation on a box and a torus.
My code as follow:
    // Boolean opeartion: Union (Fuse)
    gp_Ax2 datum;
    datum.SetLocation(gp_Pnt(500, 0, 0));

    Handle_AIS_Shape theFuseBox = new AIS_Shape(BRepPrimAPI_MakeBox(datum, 60,200,70));
    myAISContext->Display(theFuseBox);

    Handle_AIS_Shape theFuseTorus = new AIS_Shape(BRepPrimAPI_MakeTorus(datum, 80, 30, PI));
    myAISContext->Display(theFuseTorus);

    myAISContext->Erase(theFuseBox);
    myAISContext->Erase(theFuseTorus);

    Handle_AIS_Shape theFuseShape = new AIS_Shape(BRepAlgoAPI_Fuse(theFuseBox->Shape(), theFuseTorus->Shape()));
    theFuseShape->SetDisplayMode(AIS_Shaded);
    myAISContext->Display(theFuseShape);

The result see the picture in the upload file.