Abstract: In order to insure the successful implementation of CO₂ miscible flooding project in Gao 89-1 block,an 3D model was built on the basis of reservoir geologic characters based on the results of fine reservoir description of Gao 89-1 block and the optimized model of CO₂ injection.The numerical development indexes are calculated and the influence of five parameters（including well pattern,development method,pressure level,cumulative injection,and oil recovery rate） is optimized.The appropriate project commendatory in oil field application is presented at last,the oil recovery will reach to 23.10%,increasing by 15.16% than elastic exploitation.