Based on the empirical study of Lishui village in Nanjing， it is found that as an important technology in grassroots governance reform， 12345 mayor's hotline to intervene in small and micro contradictions enhances the rationality of village dispute mediation subjects， and standardized village cadres eventually replace rural ones， highlighting the standardization trend.as follows： break the middle level to absorb conflict， rely on the pressure system to distribute conflicts， deal with conflict in accordance with the textual norms， and assess conflict according to subjective standards.The characteristics are the subjects specialization and the logic centralization. 12345 mayor hotline promote the standardization but causes a series of consequences to be vigilant. Standardized dispute mediation subject is the extension of rational power in bureaucratic system. The consequences of its emergence in irregular rural society are conducive to the practical improvement and theoretical reflection， such as the extending reflection on rational governance methods and compatibility of governance with different degrees of rationality， the ideal boundary of state involvement in society.