The equivalent effect relationship formula of LOCA hydraulic load in the bend section of the heat transfer tube of the steam generator is deduced. The hydraulic load factors affecting the stress of the heat transfer tube are derived. The spectrum analysis of the corresponding LOCA hydraulic load is carried out, and the spectral curve of the hydraulic load and the spectral characteristics of the hydraulic load are obtained. Modal analysis of steam generator heat transfer tubes is done. The modal analysis of the steam generator heat transfer tubes is performed. The spectral characteristics of the hydraulic load and the natural frequency information of different heat transfer tubes are compared. According to the comparison results, eight heat transfer tubes with the first-order natural frequency and the frequency corresponding to the peak value of the hydraulic load in the frequency domain curve were selected as the analysis objects, and the LOCA dynamic response analysis is carried out. The time-domain analysis of the LOCA hydraulic load of the steam generator heat transfer tube was performed, and the relationship between the hydraulic load and the bending radius of the heat transfer tube was obtained. The transient load of the steam generator heat transfer tube with different bending radii is calculated. By establishing the finite element models of the first, 31, 43, 57, 72, 83, 87, and 112 rows of heat transfer tubes, the time history analysis of the heat transfer tubes under the LOCA load is performed, and The stress distribution of the heat transfer tube under the LOCA load is obtained. The stress of the heat transfer tube calculated by this method is the maximum LOCA response. This method can screen out sensitive heat transfer tubes, avoiding the process of analyzing each heat transfer tube. This method can effectively improve the efficiency of LOCA analysis of heat transfer tubes and is a practical method.