model comparison tests of SMW engineering method and shaped steel exterior-protected construction are proceeded by loading on active side to simulate unloading on excavation side. Test results show that: shaped steel and cement soil of SMW engineering method can be a whole body and perform jointly compared with single shaped steel exterior-protected construction because of cement soil enclosing of shaped steel

so that stiffness of shaped steel is increased; and horizontal displacement can be decreased effectively. Internal force of SMW is less than that of single shaped steel exterior-protected construction obviously because of cement soil; this is accordant with actual measurement of engineering. Performance character and interacting mechanism of SMW are discussed from various angles.