from capital airport to hotel Beijing Badaling hot spring resort how we can reach only by train

Do you refer to Jinyu Badaling Spa/Hot Spring Resort? If so, I'm afraid no train can take you there directly. You need take Airport Express Train to Dongzhimen Station, where you need to transfer to subway line 2 to Jishuitan. Upon your getting off, you can turn to the local person to ask the direction to Deshengmen. Then take Bus 919 (Deshengmen to Yanqing) there and get off at the terminal. You will easily find the resort.