Abstract: To solve the problem of plant protection of agricultural robots in mountain citrus orchards in Guangxi, a plug-in track chassis based on STM32 microcontroller is designed, which can be used as a power chassis for transportation, mowing, picking and spraying equipment.Add-on Track chassis Includes frame, control chassis two 1.5 kW permanent magnetic DC brushless motors power system for the 48 V lead battery with a 6 kW range increases and a machine control system based on the main controller of the STM32.Chassis The main controller is the STM32,and Remote control of the track chassis via Bluetooth signal on the mobile APP,automatic plant protection can also be achieved by entering the program inside the main controller control track chassis.By simulating field testing of mountain orchards, the track chassis can accurately walk on specified routes and perform plant protection operations at fruit trees.