A set of liquid surface tension coefficient measuring new device is designed by using the simpleconcept of mutual balance of surface tension , buoyancy and gravity.The experimental results show that thedevice is used to measure the surface tension coefficient of deionized water and tap water ,and the results are ingood agreement with the standard result. Compared with the pull-out method based on tension sensor, them easurement accuracy is largely improved.The device has the advantages of simplicity,high precision and lowcost,and can provide a new method for measuring liquid surface tension coefficient.