Based on the cleaning of the secondary side in High-Temperature Gas-cooled Reactor(HTR-PM) steam generator. the compressed air blowing technology are proposed in this paper. Through the analysis on the flow behavior of steam-water two-phase or one-phase in helical coils of the secondary side in the steam generator,the method of blowing coefficient was introduced.According to the design parameters of the unit, the result showed that the compressed air blowing technology is feasible.