Discrete element method (DEM) is getting a wider use in granular media study. It is a fundamental of lunar soil DEM study that matching the micromechanical parameters of lunar soil simulant with its macro parameters. In this paper, the matching work is carried out by simulating triaxial test applying PFC3D software, and the constitutive model is a parallel-bonded (PB) model to match the physical characteristics of high-dense lunar soil simulant. We first discuss the influence of different DEM parameters on peak strength of the soil. We then discuss the role of particle size in the simulation work, and find the key parameter that determines the deformation rate. Finally, two sets of matched DEM parameters are obtained with different particle size. This paper may provide a guidance for the parameter match work between different kinds of DEM constitutive model and soil.