Abstract: A Lagrangian point-particle solver is developed based on the open-source framework of the NNW-PHengLEI software. A particle source term is included in the solver to realize the two-way coupling between fluid and particle, and analyze the modulation law of particles in the compressible flow. In this work, we first introduce the particle force models, numerical methods, boundary conditions, interpolation methods of flow parameters, etc. involved in the particle solver in detail. Furthermore, based on the literature and theory on the particle motion trajectories in classical Poiseuille flow and the impact of particle motion in boundary layer flow, the particle solver is validated, demonstrating the solver's capability for two-phase flow simulation. We also conduct a preliminary study on the particle-flow interaction in a compressible laminar boundary layer flow over a flat plate. It is found that, with the simulated parameters, the presence of micron particles significantly increases the skin-friction coefficient and heat flux, and decreases the boundary layer thickness, while the particles gradually deposit to the wall along the flow direction.