Direct numerical simulation of particle growth in fluid flow is still challenging, because of the limited information available in experiments. To simulate particle growth in fluid flow, fluid-particle interactions must be considered along with particle growth models in an integrated model of numerical methods. In recent times, immersed-type methods have succeeded in simulating multiple solid objects in fluid flow. Furthermore, various interaction forces on particles can be included in a simulation model. In this study, an immersed Lagrangian point method was proposed to simulate a particle growth model in fluid flow, specifically, Taylor–Couette flow. The agglomeration and deagglomeration processes of particles were described in the simulation model. The simulation model was compared against actual experiments of particle growth in fluid flow and tested using various sets of particle growth parameters. Finally, the potential and future perspectives of the suggested model were fully discussed.