Abstract: The stability of tunnel working face is the prerequisite for safe tunnel construction. Taking the shallowburied tunnel in soft surrounding rocks as the research object, based on the strength reduction theory, a judgment process for working face stability is established and safety factor of stability can be solved; the instability criterion is analyzed, and it is considered that criteria of abrupt change of displacement or plastic strain energy can be adopted for judgment of working face stability; on the basis of the Jiaheyuan underpass, the countermeasures for working face stability are studied, stability safety factor is used to pre-evaluate the reinforcement effect of single and combined pre-reinforcement measures, and the pre-reinforcement method for working face is determined.