The invention relates to a control method of a soft landing autonomic obstacle avoidance fixed-thruster, and belongs to the technical field of deep space detection. The control method comprises the steps as follows: firstly, a target landing point is selected by using earth surface obstacle information formed by an optical camera and an obstacle detection device of the optical camera during the detector lowering process, then the position information and the attitude information of the detector are acquired by using the optical camera and navigation equipment such as an altitude meter and a speedometer, and a kinetic equation containing the thruster is established; a reference kinetic equation is established according to the pre-determined obstacle avoidance track; and finally, through the steady state error kinetic equation, the fixed-thruster is controlled to be opened or closed in real time, the reference ground track tracking is finished, and the detector is safely and stably lowered to the target landing area. The control method has the characteristics of simple algorithm, small calculated amount, high control accuracy, and low fuel consumption.