Abstract: In Dagang oilfield,the productivity construction was in deep layers for old oilfield development,and the high temperature in deep layers and pressure system disorder of old oilfield brought new challenges for cementing.Through experimental research of factors influencing on high temperature well cementing in deep layers and cementing quality of adjustment wells in old area,effective measure to improve the cementing quality of adjustment wells were provided,such as shortening thickening time,optimization of drilling fluid system,enhancing slurry mixing temperature.After the implementation in 2012,the cementing quality was improved obviously.