An autonomous control method autonomously controls a small unmanned helicopter toward target values, such as a set position and velocity, by deriving model formulas well suited for the autonomous control of small unmanned helicopters, by designing an autonomous control algorithm based on the model formulas, and by calculating the autonomous control algorithm. The autonomous control system includes sensors that detect current position, attitude angle, altitude relative to the ground, and absolute azimuth of a nose of the small unmanned helicopter; a primary computational unit that calculates optimal control reference values for driving the helicopter from a target position or velocity values; a secondary computational unit that converts data collected by the sensors and the computational results as numeric values that are output by the primary computational unit into pulse signals; a ground station host computer used as the computational unit for the autonomous control system; and so on.