Owing to the grid structure and load increase，grid thermal stability has become increasingly conspicuous.From the practical perspective of steady-state data，the thermal stability control subsystem is developed in energy management system for short-term and temporary grid thermal stability overload.By means of the automatic remote control，thermal stability control can be executed in a minute by cutting off remote load and generator unit thereby improving the ability of power supply by relaxing the thermal limit.The principle and implementing method of thermal stability control of the master station are dealt with.And some key techniques are presented，including control strategy management，three-phase tripping accident determination，overload recognition and elimination.Actual application validates the effectiveness of this technology.