Objective The anxiety of college students was induced under laboratory stress, and the effects of inhalation of Cang-ai volatile oil(CAVO) on physiological indexes related to this emotion were observed. Methods 108 college students who met the recruitment criteria were selected and randomly divided into CAVO group, Cinnamomum camphora leaf oil group and blank group(36 cases/group). All subjects in each group were subjected to "three-digit continuous reduction of 17" mental calculation to induce anxiety. After excluding those who did not respond to stress, there were 30 cases in C. camphora leaf oil group, 30 cases in CAVO group, and 31 cases in blank group. There was no statistical difference in anxiety related indexes in baseline and stress period in the three groups, and there was a balanced comparison. Except for the blank group without essential oil intervention, the other two groups were intranasally inhaled C. camphora leaf oil and CAVO respectively, the total heart beats, systolic blood pressure(SBP), diastolic blood pressure(DBP) and LF/HF in the baseline period, stress period, intervention period and recovery period of the trial were measured, and compared them between and within groups. Results Firstly, intra group comparison: LF/HF, total number of heart beats, SBP and DBP in the three groups were higher than those in the baseline period(P<0.05), there was no difference between intervention expectation and stress period in blank group (P>0.05). LF/HF, total heart beats, SBP and DBP in CAVO group during the intervention period were lower than those in the stress period(P<0.05), and there was no significant difference from the baseline period and recovery period (P>0.05). LF/HF, SBP and DBP in Cinnamomum camphora leaf oil group during intervention period were lower than those in the self-stress period(P<0.05), higher than those in the baseline period and recovery period (P<0.05). Secondly, comparison between groups: LF/HF and SBP in CAVO group group during the interver Period were lower thom those in other two groups, and DBP was lower than that in blank group(P<0.05). Conclusion Under the condition of laboratory stress, after inhaling CAVO through the nose, the physiological indicators related to anxiety of college students decreased significantly, which could alleviate the anxiety induced by stress.