The invention discloses a system and method for thermal power unit monitoring and power generation plan. The system comprises a thermal power unit monitoring module and a power generation planning module. The thermal power unit monitoring module collects and monitors operation data of a thermal power unit. The power generation planning module adjusts an output power curve of the thermal power unitaccording to the data fed back from the thermal power unit monitoring module, and makes a day-ahead power generation plan and an intra-day daily power generation plan. The method is based on the thermal power unit monitoring module and the power generation planning module to make the intra-day power generation plan. The system and method in the invention can monitor the operation condition of thethermal power cogeneration unit in real time and adjust the power generation curve of the thermal power cogeneration unit based on the measured steam supply flow and a heat supply condition diagram to form the intra-day power generation plan, thereby realizing the automatic load distribution of the thermal power cogeneration unit and deep optimization of power dispatch.