Abstract: In in-service thermal power units,the phenomenon of over-temperature tube burst occurs from time to time due to the uneven heating caused by impurities in the boiler heating surface. If the pipe blowing is still carried out according to the pipe blowing method of the newly built units, it is not only time-consuming and laborious, but also costs a lot of money. In order to deal with this problem,a technical method suitable for boiler pipe blowing in-service thermal power plants is put forward,and the appropriate pipe blowing scheme is determined according to the condition of the units,which helps to achieve the purpose of removing impurities on the heating surface of the boiler,and the effect is favorable.