Air corona discharge ionic wind exciter can generate driving force without any rotating component, which makes it commonly used in aviation and aerospace field. Although there are many explanations of the thrust generating mechanism of the air corona discharge ionic wind exciter, no existing theories can unify the experiment results obtained under various conditions. A further study is still needed. The paper focuses on the characteristics of wire-aluminum foil exciter. The experiments show that the electrostatic force acting on the wire-aluminum foil is asymmetric and the variations of the height in lengthways aluminum foil and the air pressure can change the electrostatic force. Meanwhile, with the theoretical analysis the calculation model of the force of the wire-aluminum foil exciter’s corona discharge is established by taking the influences of corona layer and space charge into consideration. The calculation fits the measured value. By combining with the theoretical analysis, the thrust of wire-aluminum foil electrode corona discharge exciter is proved to come from the space charge produced by wire electrode corona discharge, which exerts an asymmetric electrostatic force on the electrode system and generates a net electrostatic force for the exciter.