Objective To investigate the cognition of e-cigarette compositions and hazards and its influencing factors among secondary school personnel （junior， senior and vocational high school） in Shanghai， so as to provide ideas for improving the cognition level of e-cigarettes among the school personnel and tobacco control efforts on campus in the future.

Methods A multi-stage stratified cluster random sampling method was used to conduct an anonymous online questionnaire survey among 1 767 secondary school personnel in Shanghai.

Results The proportion of school staff who had used e-cigarettes was 3.79%. The participants who were not sure whether the e-cigarette smoke was “mainly water vapor （incorrect）” and whether the e-cigarette smoke “contained nicotine （correct）” and “contained formaldehyde （correct）” accounted for 62.71%， 54.44% and 61.91%， respectively. Among them， 68.48%， 55.46% and 50.37%， respectively， agreed that e-cigarettes would be “addictive”， “harmful” and “that second-hand smoke was harmful”. Binary logistic regression analysis showed the following risk factors for the low level of school personnel’s awareness of e-cigarette compositions： age ≥40 years （OR=1.65， 95%CI： 1.32‒2.06）， working in junior high school （OR=1.37， 95%CI： 1.09‒1.73）， educational attainment level as junior college or below （OR=1.67， 95%CI： 1.02‒2.74）， and not having participated in tobacco control education activities （OR=1.37， 95%CI： 1.08‒1.73）. Meanwhile， working in junior （OR=1.43， 95%CI： 1.12‒1.83） or senior （OR=1.44， 95%CI： 1.08‒1.92） high school， educational attainment level as junior college or below（OR=2.10， 95%CI： 1.24‒3.56）， having used e-cigarettes （OR=2.98， 95%CI： 1.63‒5.42）， not having participated in tobacco control education activities （OR=1.49， 95%CI： 1.16‒1.92） and low level of awareness of e-cigarette compositions （OR=4.24， 95%CI： 3.44‒5.23） were risk factors for the low level of school personnel’s awareness of e-cigarette hazards.

Conclusions The level of e-cigarette awareness among school personnel in Shanghai is low， especially those who are older， had low educational attainment level and had used e-cigarettes. In the future， tobacco control education for school personnel should be strengthened to improve their cognition and ability of tobacco control on campus.