In order to establish the three dimensional（3D） mechanical model of rock filled concrete（RFC）， firstly， 3D random polyhedron was used to simulate the rock rubble， and the rock rubbles spatial random distribution algorithm and compaction algorithm were put forward； secondly， the self compacting concrete（SCC） filling algorithm was proposed to generate 3D mechanical model of RFC； finally， the mechanical properties of RFC under uniaxial compression were obtained with the established 3D mechanical model， and the calculated results were compared with the experimental results. The results show that the 3D mechanical model of RFC can not only reflect the randomness of rock rubbles size， shape and spatial distribution， but also can reflect the effect of compacting process and rock fill skeleton on the mechanical properties of RFC. With certain reliability， the RFC model can make up the limitation of test conditions and provide reference for further study of the mechanical properties of RFC.