Abstract: Abstract: Exploitation of orchard fruit picking locomotive has broad prospects and brings huge economic interests. Meanwhile, China has more complex terrains for orchard distribution, such as plain, hill and terraced hillside, which bring a big security risk for safe and stable driving of orchard locomotive. In order to monitor and prevent tipping, obstacle distance system is particularly important for orchard locomotives in its walking and picking process in the orchard. At present, most pre-alarm system researches are about anti-collision for heavy-duty vehicles or locomotives. There is no system on small vehicles in the orchard, which is working on complex terrain and whose quality is unevenly distributed in the process of moving. This article studies this anti-collision and anti-tipping pre-alarm system of orchard locomotive for further research and improvement. While orchard picker is operating in the orchard, collision and tipping happens easily due to the obstacles and rugged land, which brings danger to the orchard locomotive. In order to give accurate early warning about collision and tipping and ensure to operate orchard picker stably and reliably, this article presents the pre-warning system of anti-rollover collision based on ZigBee wireless transmission. The designed ZigBee wireless network is based on CC2530. The end device collects data from ultrasonic sensor module and spoke type pressure sensors. The design uses a pressure sensor to measure positive pressure between the body and the ground to give rollover warning by comparing with rollover threshold, and uses lateral load transfer ratio (LTR) as an indicator to determine the stability of locomotive tipping. Through the network, the sensor data is sent to the coordinator and then transferred to the computer via RS232 serial port. Alarm is working after the comparison between obtained data and the threshold value. Wireless data transmission test shows that the pre-alarm device realizes the alarm when LTR is 0.9, which prevents tipping effectively; the ultrasonic sensor can detect the obstacles within 2 m, and the error between the measured and real values is not more than 0.01 m, which meets the requirement of anti-collision; the detection data of the pressure sensor conforms to the linear formula 0.3% F·S, which meets the requirement of detection precision of orchard picker wheel pressure. The system uses ZigBee with high reliability, security and low cost, in which wireless transmission mode signals and control signals are detected by the mutual transfer between the sensor and microcontroller to solve the problems such as difficulty and poor scalability of orchard locomotive system wiring, so as to meet the sensor data transmission requirement. The locomotive is a kind of small orchard machinery and the online system is easily installed and with low cost. For the safety in operation of the orchard picker, pre-alarm system for anti-collision and anti- tipping has a significant meaning.