This study focuses on exploring the acoustic differences between synthesized Guzheng pieces and real Guzheng performances, with the aim of improving the quality of synthesized Guzheng music. A dataset with consideration of generalizability with multiple sources and genres is constructed as the basis of analysis. Classification accuracy up to 93.30% with a single feature put forward the fact that although the synthesized Guzheng pieces in subjective perception evaluation are recognized by human listeners, there is a very significant difference to the performed Guzheng music. With features compensating to each other, a combination of only three features can achieve a nearly perfect classification accuracy of 99.73%, with the essential two features related to spectral flux and an auxiliary feature related to MFCC. The conclusion of this work points out a potential future improvement direction in Guzheng synthesized algorithms with spectral flux properties.