Shield tunnel machines have been widely used in the construction of metro tunnels

channels and underground pipelines. Compared with advanced construction technologies

current design theories of shield machine can not fit the properties of soil very well. In order to improve the design theory and principle applicable to soil-shield machine system

it is necessary to take more fundamental experiment research. In consideration of that it is impossible to do large quantities of field experiments

model tests should be needed to predict the performance of prototype. Therefore

the specific relationship between model and prototype should be investigated. According to similitude principle and model test method

the similitude rules of soil-shield machine system is investigated; and the design principle of similitude model test about soil-shield machine system is established. As an example

a prototype shield machine with diameter of 6 340 mm is simulated by a microtunnelling machine with diameter of 400 mm; the model machine will drive in artificial model soil; meanwhile

the results of machine working parameters and soil deformation will be recorded. Based on these data

it is possible to improve the design theory of shield machine to fit different soil grounds.