This article introduces unbalance phenomenon when several steel wire ropes hoist skip and some main methods of measuring steel wire ropes tension in coal mine. Use the strain effects to design a sensor which can be used to measure the tension of steel wire rope, to provide reliable data for the subsequent online tension inspection system. In order to facilitate the sensor in this system, the height of the sensor needs to be low enough. As one of the most important parts of the strain sensor, the elastic body is also low-height. To solve that problem, first using the SolidWorks software modeling and analysis of elastic body to design the sizes and obtain the best patch position of strain gauge.