Objective: To use LUS independent LUS score to accurately guide the frequency of PS use in preterm infants with NRDS and TTN secondary lung consolidation. Methods: Preterm infants with gestational age < 34 weeks were selected for LUS examination and monitoring after birth. When LUS imaging indicated lung consolidation, PS treatment was given. After PS treatment, LUS was used to monitor pulmonary reexpansion and determine whether to use PS again. Result:Among the 217 preterm infants who met the study criteria, NRDS 55 (25.34%) and TTN37 (17.05%) were diagnosed combined with LUS imaging results.Among the 55 children with NRDS, the LUS examination showed complete lung reexpansion in 33 cases after the first treatment with PS, the LUS examination showed complete lung reexpansion in 14 cases after the second treatment with PS, and the LUS examination showed complete lung reexpansion in 6 cases after the third treatment with PS.LUS monitoring 37 children with TTN secondary lung consolidation 6 cases (16.22%). In these 6 children, the LUS examination after the first treatment with PS showed complete lung reexpansion in 4 cases, and the LUS examination after the second treatment with PS showed complete lung reexpansion in 2 cases. Conclusion: In the absence of LUS score, the presence or absence of lung consolidation on LUS imaging can accurately guide the frequency of PS use in NRDS children and TTN children with secondary lung consolidation.