Taking the civil aviation operation regulations of China, the United States and European Union as samples, this article makes a comparative study on the duty time of civil air crew. It can be found that compared with the United States and the European Union, China’s restrictions on duty time of civil air crew, such as flight time, cumulative flight time, flight duty period, cumulative flight duty time, duty period and cumulative duty time, are relatively ambiguous and simple, for instance, there are no clear regulations on cumulative rest period and duty in WOCL, only the report for duty time of non-expanded flight crew is divided into 12 cases (in comparison with 70 cases in the United States), and the duty time is calculated with "calendar month" as the ac? counting cycle (compared with 672 consecutive hours in the United States). All these should be improved in the future revision of civil aviation operation regulations. At present, there is a big gap between the time limit of flight crew members and flight attendants in China, which is obviously unfavorable to the latter. We should learn from the EU’s legislative paradigm of integrated protection of the two, and reduce the duty time of flight atten? dants.