Autonomous diesel vehicles and control methods thereof are disclosed. An autonomous vehicle may include a peripheral information collecting unit configured to collect peripheral information necessary for autonomous travelling through an image camera and a laser scanner, a main control unit configured to control the autonomous travelling with reference to the peripheral information collected by the peripheral information collecting unit, a passenger monitoring unit configured to check whether a passenger exists inside the vehicle through a sensor and transmit a result of the check to the main control unit, and an engine control unit configured to control driving of an engine and injection of fuel of an injector according to a control instruction of the main control unit. When the passenger is inside the vehicle, the main control unit performs a pilot injection control, and when the passenger is not inside the vehicle, the main control unit omits the pilot injection control.