<p>Laser electrochemical machining is an innovative composite processing method, achieving high surface quality and efficient shaping for difficult-to-machine materials through the combined effects of laser and electrochemical energy. Electrochemical machining adjusts the parameters of the physical field to eliminate the recast layer generated by laser ablation. In addition, the increase in electrolyte temperature caused by the laser can promote electrochemical dissolution. This work proposed a new multiphysics simulation model to explore the structure formation mechanism based on the temporal variations of temperature, electric, and flow fields during composite processing. The laser-coupled electrochemical machining used a three-current model. The temperature field variation considered not only the laser irradiation factor but also the effect of convective heat transfer induced by fluid flow. Moreover, temperature variation influences electric and flow fields, changing the physical parameters of electrolytes, such as conductivity and dynamic viscosity. Transient deformation geometry was used to uncover the material removal process during composite machining and then predict the final profile of the obtained structures. The manufacturing process could be elaborately described by the multiple physical fields using the established simulation model. Finally, an experimental study was conducted to validate the reasonability of the proposed simulation model. The role of laser effects in composite machining was also highlighted through the comparison of theoretical and experimental results.</p>