Objective To investigate the interventional and protective effect of low-dose L-carnitine（LC） against reproductive system damage in male Wistar rats during acute exposure to simulated high-altitude environment. Methods A total of 24 specific pathogen-free male Wistar rats，aged 12 weeks，were randomly divided into control group，high-altitude model group，and LC intervention group ［intraperitoneal injection of LC at a dose of 50 mg/（kg·d）］，with 8 rats in each group. The rats in the control group were fed under normal conditions（at an altitude of approximately 1 500 m），those in the high-altitude model group，and those in the LC intervention group were fed in a hypobaric oxygen chamber（at a simulated altitude of 6 000 m）. The rats were sacrificed after 3 days. The testis was collected to calculate testicular index；the semen was collected from the epididymis，and the Weili sperm quality analysis system was used to assess sperm quality；blood samples were collected from the abdominal aorta，and ELISA kits were used to measure the serum levels of testosterone（T），luteinizing hormone（LH），and follicle-stimulating hormone（FSH）；testicular tissue samples were collected，and biochemical kits were used to measure the activity of reactive oxygen species（ROS），malondialdehyde（MDA），and superoxide dismutase（SOD）；testicular tissue was collected to prepare HE and electron microscopy sections，and a light microscope and a transmission electron microscope were used for observation. Results Compared with the blank control group，the high-altitude model group had significant increases in the levels of T，LH，and FSH（P<0.01），testicular tissue damage under the light microscope，and changes in the morphology of spermatogenic cells，including mitochondrial alterations，membrane edema，loss of cristae，swelling of the matrix，and local dissolution，as well as significant increases in the levels of ROS and MDA（P<0.01） and a significant reduction in SOD activity（P<0.01）. Compared with the high-altitude model group，the LC intervention group had a significant increase in the level of T（P<0.01），significant reductions in the levels of FSH and LH（P<0.01），and significant improvements in the pathological changes of testicular tissue，with no marked mitochondrial injury，and there were significant reductions in the levels of ROS and MDA（P<0.01） and a significant increase in SOD activity（P<0.01）. There was no significant difference in testicular index between groups（P>0.05）. The high-altitude model group had a significantly lower sperm count than the blank control group（P<0.05），while there was no significant difference in sperm count between the LC intervention group and the blank control group（P>0.05）；there was no significant difference in sperm motility between groups（P>0.05）. Conclusion Low-dose LC can improve reproductive system damage in rats during acute exposure to simulated high-altitude environment，possibly by alleviating oxidative stress response.