Abstract: To determine the attitude of roll angle of projectile in acute changing situation, a sensor measurement scheme was designed, which includes high and low range configuration. Unscented Kalman filter was applied to estimate the attitude of roll angle of projectile. Furthermore, two sorts of data fusion algorithms, state fusion and measurement fusion algorithm, were designed to improve the measurement precision of roll angle in mid stage flight. Simulation study shows that the measurement data fusion algorithm has high precision and excellent performance in real-time.