Based on interviews and standardized accessing, the paper describes the status quo of work and life of the substitute teachers in western rural areas of China during the period of social transformation. The results show that, the substitute teachers are aged and senior with more contribution and valuable spirit, but their economic income and social position are lower, therefore they have a strong sense of identity anxiety and obvious contradictory psychology. Analysing the historical contribution and practical function of the substitute teachers, the author discusses the way to solve the problem of substitute teachers.