Abstract: Targeting and monitoring island reefs have important strategic significance in safeguarding our national interests. But high-precision positioning of island reefs with satellite imagery often lack controls and fails to achieve its target; thus, the important research value of realizing island reefs targeting under scarce control conditions. In the paper, a Mapping Satellite-1(TH-1) image was taken as the research object. A strict imaging model was established for TH-1 satellite images and TH-1 satellite image island reef positioning was proposed and implemented without controls, based on orbit extrapolation and scarce control of TH-1 island reef satellite image positioning based on orbit extrapolation. An Experimental, analysis tested the feasibility of improving TH-1 geometric positioning of island reefs by orbit extrapolation techniques without controls and with scarce controls. The results demonstrated that the methods without control positioning technology based on orbit extrapolation and scarce control positioning based on orbit extrapolation were the best ways for targeting positioning of island reefs. These approaches can greatly improve positioning accuracy for key sea targets with no controls or under scarce conditions.