A finite element model (FEM) based on numerical model is established to study the process of laser-assisted pre-stress forming and further verified with experimental data. Based on the verified FEM model, the effects of pre-stress and laser parameters on forming efficiency are investigated via a set of dimensionless quantities. A higher pre-stress level results in a higher forming efficiency in the elastic range. A larger beam radius at constant scanning velocity and power density, or a higher power at constant scanning velocity and beam radius, or a faster scanning velocity at constant beam radius and injected energy, results in a higher forming efficiency.