Micro air vehicles (MAVs) are becoming more popular over larger unmanned aerial vehicles (UAVs) as they are easily portable, more discreet and less dangerous in case of a crash. Among common types of MAVs, the flapping wing configuration shows incredibly potential flying skills such as hovering, flying backward and recovering after shock. However, designer faced many difficulties due to the microsize of the MAVs. In this work, we propose a numerical model based on Bond Graph for our flapping MAV which allows us to analyze the wing kinematic and thus predict the total lift force. This Bond Graph model employs the quasisteady aerodynamic theory and the Lagrange dynamic equation as the main principles. A proper wing kinematic which allows the enhancement of the total lift force could be derived from this model based on the non-linear optimization of the system‘s sensitivity parameters such as spring stiffness, working frequency and input voltage... A prototype is fabricated and characterized. Comparing the experiment and the simulation, the model is able to predict the wing movement and the mean lift force, and therefore could be used as a design tool. A take-off demonstration is provided to confirm our results.