Sanitation workers are the epitome of urban lower-level laborers,and also represent an indispensable occu-pational group for the normal operation of urban life.Based on the theoretical basis of rational choice,this paper outlines the group profile and realistic situation of sanitation workers through field investigation in Longshang Neighborhood of Shang-hai,and systematically discusses the action logic and internal tension of sanitation workers'career choice from the dimen-sions of survival rationality,development rationality and value rationality.It is found that the career choice of sanitation workers is a coupling process of survival rationality,development rationality and value rationality,which not only has the synergy between survival rationality and development rationality,but also the competition and cooperation between instru-mental rationality and value rationality;it is also a complex product of active choice and passive choice with structural con-straints.