The automatic plant startup and shutdown control system (APS) of ultra supercritical unit was studied and analyzed in this paper. According to the difficulties and features of APS design, complete architecture structure and hierarchical control method of APS system were proposed. The interface software between APS and modulation control system (MCS) was developed. The whole process control strategies of feed water system, fuel system, air-flue gas system, bypass system and deaerator water level system were optimized. These strategies realized the whole process control of fuel, feed water and induced & draft fan. The special control strategies of main steam temperature, boiler dry-wet state transition and hot cleaning were also proposed in this paper. It first realized the automatic startup and shutdown of ultra supercritical unit in China.