As an effective forming technique, peen forming is widely used in sheet metal components with large dimensions. However, the production efficiency is seriously limited as several peening tests are required before actual production. To address this issue, a numerical simulation method of peen forming was proposed. In this work, an elastoplastic peening finite element model was developed to study the relations between process parameters and forming effects. A set of peen forming tests with different coverages and velocities were conducted to validate the model. Results indicate that the maximum errors of converted arc height and forming curvature are less than 5% and 14%, respectively. Additionally, the saturation phenomenon can be observed as the peening coverage reaches 60%. The corresponding depth of the maximum compressive residual stress varies almost linearly with shot velocity.