In the era of flexible working hours, western countries generally adopt the transformed working hours system to realize the flexible regulation of labor benchmark of overtime hours, and mitigate the negative effects caused by the lack of mandatory benchmark of overtime hours by expanding workers' autonomy in working hours. In order to solve the problem of rigid legal regulations on the labor standard of overtime hours arrangement in China, the Labor Law should break the boundary between the comprehensively calculated working hour system and the standard working hour system, organically combine the two, expand the flexibility of the mandatory standard working hour benchmark application, and achieve the flexibility of overtime hours regulations. In order to reduce overtime hours, the current total annual working hours shall be used as the upper limit, and a flexible regulation of overtime hours with a reference period of 3 months shall be adopted, clearly stipulating the maximum number of working hours per day and per week during the reference period. At the same time, the compensatory rest system for work overtime and the determination process for work overtime arrangement shall also be improved to ensure the autonomy of workers' time, thus achieving the regulatory goal of balancing “flexibility” and “safety” in “overtime hours arrangement”.