The soft soil of silt underneath the miscellaneous fill can be easily squeezed into the pores between the particles of the miscellaneous fill under overlying loads, resulting in mutual embedding settlement, which is failed to be taken into account in traditional foundation settlement calculations. But miscellaneous fill has the property of uneven grading, and its porosity is closely related to its particle size component. This paper selected four different particle size groups, a binary mixture of heterogeneous soil particles of different particle sizes was studied, used self-made embedded instrument to investigate the evolution pattern of total settlement and mutual embedded settlement under the different particle size ratios and small particle content of miscellaneous fill by tests. The results indicate that: under binary mixed granular composition, when small particles occupy the body, mutual embedded settlement increases with increase of small particle size, when the content of large and small particles is the same, the mutual embedded settlement tends to decrease first and then increase with increase of the particle size of small particles, when the content of small particles is less, the mutual embedded settlement decreases with increase of particle size; and in the process of particle content change in miscellaneous fill, when the particle size of the small particle is small, mutual embedded settlement decreases with increasing particle content, when the particle size is large, the increase of particle content does not have much effect on the intermixing settlement between the miscellaneous fill and the soft soil.