Abstract: The repeatability and reliability of the cone penetration test(CPT) have increased its acceptance as a predominant choice in in-situ test techniques.Using particle flow code in 2-dimension(PFC2D) to study the meso-mechanics of cone penetration test is a good way,and it will be helpful to the service for practical engineering.The discrete element method(DEM) method is of some predominance in the simulation of soil large deformation.Thus PFC2D program was applied here.The driving process of cone,the distribution of displacement and stress of adjacent soil were analyzed,and the isoline of displacement and stress field was drawn.At the same time,the rotation of principal stresses was analyzed.Especially,the stress boundary conditions were applied to different boundaries to obtain different stress states,and the emphasis was laid on the effect of different stress conditions and OCR on the cone tip resistance.The conclusions in this study would be useful to the model study of CPT and its engineering application.