The invention discloses a master-slave burden type redundancy automatic unmanned aircraft pilot based on a CAN bus. The automatic unmanned aircraft pilot comprises a main controller module, a sensor module, a steering engine controller module, a wireless communication module and an extension module. All modules are in data communication through the CAN bus. The main controller module adopts the master-slave burden type redundancy working manner, thereby improving the real-time performance, reliability and fault-tolerant ability of the automatic pilot; the sensor module comprises an atmospheric engine, a GPS receiver and an inertia measurement unit, and obtains all accurate and stable attitude information and navigation information of the unmanned aircraft; the steering engine controller module adopts the control method of a single chip, utilizes a 555 timer to provide an oscillating impulse to generate multi-path PWM signals, reduces mutual interference between signals of the steeringengine through separate power supply and optical coupler insulation, and realizes high precision control on the multi-path steering engine. The invention which adopts the modularization of the CAN bus improves the flexibility, and realizes the design purposes of miniature and low cost.