In order to ensure daily scheduling has dispatching and financial meanings， how to transform the daily generation scheduling into real-time dispatching instruction in day-ahead power market is presented. Combined with the ultra short term load forecast and actual status of day-ahead power market， the principal distribution strategy based on daily scheduling and three ancillary distribution strategies respectively based on regulation margin， completion rate of annual generation schedule and contract price are proposed. Furthermore， such important problems as the load flow control of transmission interfaces， the emergency control and transforming mechanism to improve control performance standard（CPS） index， and reinforcing the ability of anti-interference are illuminated in detail. The design idea presented has been implemented in the ultra short term real-time dispatching system of Zhejiang power grid， and has been proved to improve control quality and ensure the justice of market clearing effectively.