In this paper, we proposed a new method to identify vinegar. First, we obtained the ultraviolet spectrum curves(samples) of five kinds of vinegar by ultraviolet spectrum scanning technology. Then, the samples of five kinds of vinegar were trained and tested by improved Multi-class Support Vector Machines(MSVM) for identification. The experimental results indicate that the method of combining ultraviolet spectrum technology and improved multi-class support vector machines is effective and accurate. The identification accuracy is 100%.