If an elderly person lives alone and accidentally falls indoors or outdoors, she / he will not receive timely medical assistance and treatment, which will cause huge psychological and physical harm. In this paper, the attitude and heading reference system (AHRS) is used in fall detection, and the fall process is transformed into a change in attitude to judge the degree of fall. The AHRS attitude and heading system has been improved from the previous three experimental attitude angles, the pitch angle is increased by 2. 371%, the roll angle is increased by 9. 238%, the yaw angle is increased by 4. 682%, the maximum accelerometer accuracy is 0. 171g. The system fusion extended Kalman filter has improved the detection time calculation of the elderly by 1 second compared with the original experimental scheme in the past. In summary, the experiment proves that the AHRS attitude and attitude fusion can detect the fall of the elderly with more accurate data and less calculation time, which is a step closer to study the real fall posture of the human body.