In the experimental process of measuring liquid surface tension coefficient by pull-off method，there are many factors that influence the experimental results． Four factors that have significant influence on the experiment are summarized and analyzed by theoretical analysis，namely，the error of surface tension coefficient caused by temperature measurement deviation; Incorrect k value caused by rust or wear of weight leads to error of surface tension coefficient; The surface tension coefficient error is caused by the change of △U caused by the water on the ring，and the surface tension coefficient error is caused by the measurement error of the inner and outer diameters of the ring．The analysis results show that the surface tension coefficient measured by the experiment will gradually decrease with the increase of temperature，and its measurement error will be

aggravated with the increase of the number of rusty weights，the mass of water droplets attached to the ring and

the measurement error of inner and outer diameters．The research results can play a guiding role in reducing the

measurement error of liquid surface tension coefficient by pull-off method in the experimental teaching process

of college physics teaching．