The freezing phenomenon of a freefalling droplet widely exists in spray crystallization and artificial snowmaking. In this study, this process is investigated by an improved enthalpy-based lattice Boltzmann method. The latent heat of the phase change and the forced convection heat of the fluid flow are included in this model, respectively. The solid volume fraction is introduced in the particle distribution function of the migration equation. Firstly, it is validated through comparison with the analytical solution in a good agreement. Then the model is applied to study the temperature field, the solid volume fraction and the solid-liquid interface position in the droplet. Finally, the effect factor of the freezing time is tested via a series of numerical simulations. (C) 2017 Elsevier Ltd. All rights reserved.