The effects of different processing and drying methods on overall metabolites of Eucommiae Cortex were investigated. First of all，the rough skin on the surface of fresh Eucommiae Cortexes were scraped off，some of them were stored in the refrigerator at －80 ℃，and the rest were treated with three kinds of different processing and drying methods，including stacking “sweating”，scalding “sweating” and drying in the shade. Secondly，three kinds of processed and dried Eucommiae Cortex，including fresh Eucommiae Cortex samples，were freeze-dried，crushed and then extracted with 70% methanol. The metabolites of Eucommiae Cortex were analyzed by ultra performance liquid chromatography－tandem mass spectrometry（UPLC－MS/MS） with electrospray ionization（ESI） ion source，and positive or negative ion mode was used for data collection. The collected data were processed in a series of ways，including peak extraction，peak integration，normalization，etc. After that，the molecular weights of metabolites were obtained according to the first-order mass spectrometry information. And the characteristic ion fragments of metabolites were obtained with the second-order mass spectrometry information，so as to realize the structural analysis of modern metabolites. By searching Metware database（MWDB），human metabolome database（HMDB），MassBank and other databases，the qualitative analysis of metabolites in Eucommiae Cortex was carried out. Finally，the metabolite data were analyzed by principal component analysis（PCA），orthogonal partial least squares discriminant analysis（OPLS－DA） and other multivariate statistical analysis. On the basis of variable importance in the projection（VIP） obtained by OPLS－DA model and fold change（FC），the different metabolites in Eucommiae Cortex obtained by different processing and drying methods were selected. The relative contents of metabolites were characterized by relative peak area，and the relative contents of different metabolites were compared. Results showed that the Eucommiae Cortex samples of the four groups could be clearly distinguished in the PCA score diagram. More than 170 metabolites in Eucommiae Cortex obtained by three kinds of processing and drying methods changed significantly，compared with those in fresh Eucommiae Cortex. And more than 80% of the metabolites were up-regulated. Among the Eucommiae Cortexes obtained by three kinds of processing and drying methods，the number of up-regulated metabolites of stacking“sweating”Eucommiae Cortex was higher，followed by that of drying in the shade. In addition，stacking“sweating”was conducive to the retention of lignans，coumarins，iridoids and quinones，drying in the shade was conducive to the retention of phenolic acids，and scalding“sweating”was conducive to the retention of flavonoids. By comparing the different metabolites of Eucommiae Cortex with different processing and drying methods，a scientific basis was obtained for exploring the quality formation mechanism of Eucommiae Cortex and optimizing its processing methods.