Objective To explore the difference of clinical effect of nasal intermittent positive pressure ventilation（NIPPV）and nasal continuous positive pressure ventilation（NCPAP）as non-invasive respiratory support mode after extubation in preterm infants with endotracheal intubation．Methods Sixty-six cases of preterm infants with neonatal respiratory distress syndrome treated in our hospital from January 2021 to June 2023 were included．All the subjects were randomly divided into NIPPV group（n=33）and NCPAP group（n=33）．The blood gas analysis results,weaning failure rate,non-invasive respiratory support time,oxygen inhalation time after noninvasive ventilation,total oxygen administration time．were compared between the two groups．Results After 12 hours of noninvasive respiratory support,PaO₂ in the NIPPV group increased to（76.46±1.10）mmHg,which was significantly higher than that（75.51±2.15）mmHg in the NCPAP group（t=2.249,P=0.028）．In addition,SaO₂ in the NIPPV group increased to （96.36±0.52）%,which was also significantly higher than that（96.07±0.59）% in the NCPAP group（t=2.138,P=0.034）．The PaCO₂ in the NIPPV group decreased to （41.39±0.74）mmHg,which was lower than that（41.87±0.95）mmHg in the NCPAP group（t=-2.230,P=0.025）．The duration of non-invasive respiratory support in the NIPPV group（3.09±0.52） days was shorter than that（3.45±0.62）days in the NCPAP group,and the difference was statistically significant（t=2.584,P=0.012）．Similarly,the total duration of oxygen administration in the NIPPV group（9.52±0.76）days was shorter than that（10.00±0.79）days in the NCPAP group,and the difference was statistically significant（t=-2.548,P=0.013）．There were no significant differences in weaning failure rate,oxygen inhalation time after noninvasive respiratory support,and incidence of adverse reactions between the two groups（P>0.05）．Conclusions Compared with NCPAP mode,NIPPV mode for non-invasive respiratory support in preterm infants after extubating has better clinical effect,and it is worthy of clinical application．