This article analyzes the performance of light fidelity (LiFi)-based device-to-device (D2D) communication in industrial Internet-of-Things (IIoT). We present a comprehensive analysis of mobility management of D2D communication in industrial LiFi networks. Using the semiangle at half illuminance of the AP and D2D transmitting IIoT, a coverage model for the D2D communication range is derived. By adopting stochastic geometry, closed-form expressions for mode selection rate and residence time are derived as functions of the AP density, IIoT density, and velocity. The results have shown that high velocity and denser deployment cause a decrease in the average D2D residence time and an increase in the average D2D transition rate or vice versa. The proposed analytical models are then verified with Monte Carlo simulation results. The results provide system-level design insights.