Objective：To investigate the role of PTEN induced putative kinase 1（PINK1）/parkin-mediated mitophagy in diaphragm dysfunction caused by mechanical ventilation（MV）. Methods：Twenty-four adult male SD rats were randomly divided into the Control group（n=6），the MV-6h group（n=6），the MV-12h group（n=6），and the MV-24h group（n=6）. Rats in the Control group were without any treatment，in the MV-6h group were mechanically ventilated for 6 h，in the MV-12h group were mechanically ventilated for 12 h and in the MV-24h group were mechanically ventilated for 24 h. Using RM6240 multi-channel physiology signal collection and pro－cessing system was used to detect diaphragm compound action potential（CMAP），hematoxylin and eosin staining method was used to measure the cross-sectional area（CSA） of the diaphragm，and Western blot was used to detect levels of muscle atrophy F-box（MAFbx），muscle specific ring finger 1（MURF1），mitochondrial fission protein（drp1），mitofusin-2（mfn2），autophagy-related protein of PINK1，parkin and P62，and microtubule-associated protein 1 light chain 3（LC3）. Results：The amplitude of CMAP in the MV-12h group[（3.15±0.52） mV] and the MV-24 group[（2.44±1.26） mV] was significantly decreased（P=0.000）. The duration of CMAP in the MV-24h group[（7.05±0.61） ms] was significantly longer（P=0.000）. Compared with the Control group[（5 308.67±228.18） μm2]，the CSA of diaphragm in the MV-6h group[（3 378.33±393.40） μm2]，the MV-12h group[（2 969.67±35.16） μm2] and the MV-24h group[（2 115.33±130.23） μm2] was significantly de－creased（P=0.000）. Compared with the Control group，the level of MAFbx in the MV-12h group[（2.59±0.19）] and the MV-24h group[（4.11±0.19）] was significantly increased（P=0.000），the level of MURF1 in the MV-12h group[（1.96±0.26）] and MV-24h group[（2.88±0.29）] was significantly increased（P=0.000）. drp1 in the MV-24h group（5.55±0.36）（P=0.000） was significantly increased and mfn2 in the MV-12h group（0.47±0.13） and the MV-24h group（0.35±0.10） was significantly decreased（P=0.002）. Compared with the Control group，PINK1 in the MV-12h group（2.53±0.25） and the MV-24h group（4.78±0.31） was significantly increased（P=0.000），parkin in MV-24h group（3.73±0.16） was significantly increased（P=0.000），P62 in MV-12h group（2.28±0.06） and MV-24h group（3.69±0.17） was significantly increased（P=0.000），and LC3Ⅱ/Ⅰ ratio in MV-24h group（1.57±1.32） was increased significantly（P=0.002）. Conclusion：MV can change the PINK1/parkin-mediated mitophagy，leading to diaphragm dysfunction and atrophy.