The study of flight orientation has gained more and more attention. In this study, we demonstrated a cyborg beetle for measuring body orientations in free flight, which contained a living insect platform and a miniature backpack with micro battery. While flying in a large flight chamber, the flight status of cyborg beetle could be recorded remotely. Thereafter, the effect of pitching on flight control was analyzed. According to the recorded flight data, a strong linear relationship was revealed between the pitch angles and forward accelerations, which was quantified by the Pearson's correlation coefficients and the fitting of mean forward accelerations under each pitch angle. We believe the coupling of pitch angle and forward acceleration is generated by tilted net aerodynamic force and flight air drag. The achievement of the orientation analysis would inspire a new approach to control system design of flying cyborgs and flapping-wing micro air vehicles (MAVs).