The invention provides a method for evaluating the running state of the blast leakage process of a heated pipe of a boiler in order to meet the requirements of rush-repair work of pipe blasts. The method comprises the steps that the heated pipe is dispersed into n pipe sections by collecting the steam pressure and temperature of an inlet collection box and an outlet collection box of the heated pipe and changes of data at outlet temperature measuring points of the heated pipe, the steam pressure and enthalpy of the next pipe section are calculated according to the steam pressure and enthalpy of the previous pipe section, and calculation is conducted in this way to obtain parameters of the other pipe sections of the heated pipe; next, leakage of the heated pipe is divided into three stages, namely the stage without leakage, the stage of insufficient development of a blast opening and the stage of sufficient development of the blast opening; evaluation is conducted according to the second stage, that is, the heated pipe with different blast opening areas is evaluated according to the steam parameters of the inlet collection box and the outlet collection box, and the size of the blast opening is evaluated according to the measured data at the outlet temperature measuring points of the heated pipe; lastly, according to the steam pressure and temperature of the inlet collection box and the outlet collection box and the leakage area, a dangerous blast opening area range is given, and then evaluation of all the pipe sections is completed.