Currently, the overwork of staff is prominent in China’s enterprise development, which need to be paid attention to and to be solved. In a perspective of individual and organizational, this paper empirically analyzed how vocational delay of gratification and career growth affect overwork of the staff, and verified relevant hypothesis through hierarchical regression analysis based on a survey of 338 employees. The results show that： (1) The vocational delay of gratification has a significant positive effect on overwork of the staff, both its two dimensions (work delay of gratification and occupation career delay of gratification) also share this effect; (2) The career growth opportunities have an obviously negative effect on overwork of the staff; (3) The career growth opportunities have a negative moderating effect on the relationship between vocational delay of gratification and overwork of the staff. That is to say, the more career growth opportunities which the employees obtained, the weaker relationships existed between vocational delay of gratification and employees overstrain. Thus, enterprise executives should reasonably guide and help the employees to have vocational career plan, provide the employees with diversified development roads in order to effectively prevent and mitigate the overwork of the employees.