The research of the rheology of multiphase complex fluids needs the information of basic mechanic process.Four-roll mill

able to generate Variety flow fields such as rotation

shear

extension and having a stagnation point at the centre of flow field

is suitable to research the deformation

breakup and coalescence of a drop immiscible with matrix or the rheological properties of complex fluids composed of fibers

solid particles

liquid crystal etc and liquids.The application scope of four-roll mill can be extended by combining with other instruments.In this paper

the development

theory basis

main components

application of four roll mill and the main work done with it are presented.Compared with other rheological apparatus

its merits and shortcomings were summarized at this paper end.