In order to study the effect of unsteady flight parameters on the aerodynamic characteristics of simulated butterflies, a flight dynamics model was established with the black-framed blue Morpho butterfly as the research object. Based on the flight principle, the relative coordinates of butterfly wings, body and ground during flight were established, and the kinematic equations of butterfly wings and body during flight were constructed. The aerodynamic characteristics of the simulated butterfly were verified based on the flight principle of the butterfly, and the effects of the change of flutter angle and pitch angle on the lift and drag of the simulated butterfly were studied under the natural environment flow field. The results show that there is a positive correlation between turning angle and lift force, but no correlation with drag. When the flutter angle is less than 120°, the lift is positively correlated, when the flutter angle is greater than 120°, the lift is negatively correlated, and the flutter angle is negatively correlated with the drag. A high pressure area begins to occur at the leading edge of the wings when the downward flapping occurs, and at the edge of the wings when the upward flapping occurs. The research results provide a reference for the control parameters and wing design of flapping wing aircraft, and provide a scientific basis for further optimization of bionic flapping wing flight.