To avoid mountain orchard monorail conveyor runs, hit a stationary obstacle in front of a moving object or crossing orbit, enhanced security and stability monorail conveyor running on the transit time method of ultrasonic ranging technology developed an avoidance barrier,comprising: SCM STM32F103RC, ultrasonic probe, ultrasonic transmitter circuit, ultrasonic receiver circuit, power supply module, serial communication module and key controllers.Regular physical blocks respectively (high 60cm, width 20cm, length 30cm), irregular stones (diameter 18cm, height 8cm) as an obstacle placed on the monorail to the branches (length 120cm, width 50cm), potted citrus trees (diameter 70cm high ll0cm) as a non-obstacle placed next to the monorail, the avoidance installed in three different positions 10, 20 and 25cm at the front of the vertical line on the front of the monorail transport aircraft, transport aircraft and a slow 1.44km / h, speed 2.88km / h and fast 4.32km / h on the road three speed monorail, obstacle avoidance test the performance of obstacle avoidance.The test results show that when placed in front of the obstacle avoidance from the track in front of the vertical height of 10cm, avoidance is to identify different objects in front of the parking distance to achieve the best security, to ensure the safety of personnel and equipment, to the actual application requirements.For secure remote mountain orchard running rail transport avoidance to provide guidance and technical support basis.