This paper analyzes the correlation between overwork and economic losses.So as to judge the impact of overwork on economic losses in China. The total economic loss is calculated by the prevention cost,medical expenditure and production loss caused by overwork.And the two-stage least square method is used to estimate the impact of overwork on economic losses.The results are as follows: when the frequency of physical and mental fatigue reaches several times a month or more,the impact on economic losses is very prominent.When the daily working hours are less than 7 hours and more than 10 hours,it will cause more economic losses.In particular, the daily working hours over 11 hours will do great harm to the economic losses.