The armature structure and characteristic parameters in electromagnetic launch systems have a significant impact on the launch performance. In order to explore the dynamic characteristics and influencing factors of composite armatures, based on Maxwell's equations and electromagnetic field theory, a mathematical model of dynamic emission coupling between embedded and semi embedded composite armatures was derived. The influence of factors such as the capacity and initial working voltage of energy storage capacitors, the number of turns of driving coils, and the structural parameters of composite armatures on acceleration performance were analyzed and studied. The influence of structural parameters a, c, and d of composite armatures on emission performance was calculated. The results show that the higher the initial working voltage and capacitance of the energy storage capacitor, the higher the emission efficiency of the composite armature. The number of turns of the driving coil in the synchronous induction coil gun also affects the firing performance of the composite armature. As the number of turns increases, the firing efficiency does not always increase. The parameters a and c have little impact on the emission performance, while parameter d has a significant impact on the emission performance. The proposed mathematical model and analysis results can provide a theoretical basis and data reference for the design of composite armatures.