Abstract： Objective:To evaluate the rationality of diving procedures and medical support through monitoring the stress, nutrition, and sleep quality of divers.Methods:The vital signs of divers were recorded by the monitor designed for high pressure condition. The bubble escape during decompression was evaluated by Doppler bubble monitor. The stress levels of divers were evaluated by the Stanford acute stress reaction questionnaire (SASRQ), and the sleep qualities of divers were evaluated by Pittsburgh sleep quality index (PSQI). The post-diving effects were evaluated by the tests of blood routine and blood biochemistry, and MRI examination of large joints (bilateral shoulders, hips, and knees).Results:The vital signs of the four divers were stable throughout the training, and there was no significant difference in the mean values of vital signs in each stage ( P>0.05). During the decompression, all Doppler bubble monitoring results were below level 2. The total scores of SASRQ before and after diving were both lower than 57 points, indicating a moderate and low stress level; the stress levels of divers decreased slightly after surfacing, but the differences were not statistically significant ( t=1.464, P=0.239). Before and after diving, the divers’ sleep quality was good, but it decreased after surfacing, and the differences were statistically significant ( t=-4.899, P=0.016). The results of blood routine test, biochemical test, and MRI of bilateral shoulders and hips of the four divers after diving were normal; the results of knee MRI showed that only one diver had a small amount of joint effusion. Conclusion:The physical and mental health of the divers in this training maintained good, indicating the procedures of and the medical support for the diving were safe and effective.