To study the effect of ultra high pressure( UHP) treatment on the quality of Pu'er tea,the changes of caffeine,tea polyphenols,amino acid content and the aroma components of Pu'er tea after UHP treatment( 100-500MPa) was studied. The sensory evaluation was also tested. The results indicated that caffeine,polyphenols and a mino acids after UHP treatment were significantly lower,which was in line with the natural aging of Pu'er tea; Sensory score of the raw tea under treatment at 300 ~ 400 MPa is higher than that of the control group,and the taste is similar to two years tea of natural aging. Compared with the control group,the mass fraction of terpenes,esters,alcohols and aldehydes increased obviously after the treatment at 300 MPa,while the alkanes and ketones decreased,α-cedrene( 1.26%),4( 14),11-Eucalyptus diene( 1. 55%),decanal( 0. 71%) and other aroma components were only found in UHP treated Pu'er tea. It is beneficial to improve the Pu'er tea flavor,and is consistent with the results of sensory evaluation. Therefore,UHP can accelerate the aging of Pu'er tea.