The SMW construction method has the advantages of simple construction process， economic reliability， high applicability and less environmental pollution. Since it was introduced from abroad， it has been widely used in the coastal soft soil areas of our country， but it is rarely used in the inland hard soil areas， and the standards and specifications are not well developed with some requirements remained controversial. This paper introduces the application and improvement of SMW piles in a foundation pit project in the complex surrounding environment in southwest Shandong， summarizes some problems that may be encountered in the process of design and construction， and puts forward corresponding solutions. It is more economical and reliable to use the method in the medium-sized foundation pit project where the surrounding environment is complex， the space for sloping is limited， and environmental protection requirements is strict. Since different software may lead to different calculation results in some degree， locally recognized software should be selected for the design stage with the appropriate model and parameters for calculation， and the calculation results are then optimized according to experience. The cement content and the water cement ratio for SMW piles directly affect the strength， uniformity and flow plasticity of cement-soil mixture， hence the difficulty and quality of steel construction， as well as the water sealing effect of the cement-soil curtain wall. But there is no unified standard for the hard soil area； thus， testing is necessary to obtain the optimum mixing ratio according to the actual site conditions.