Objective:To explore the effect of hydrotherapy combined with breathing training on lung function and mobility of patients with thoracolumbar spinal cord injury.Methods:A total of 80 patients with thoracolumbar spinal cord injury admitted to Beijing Rehabilitation Hospital Affiliated to Capital Medical University from April 2018 to March 2020 were selected as observation objects.A prospective cohort study was conducted and randomly divided into observation group and control group with 40 cases in each group.The control group was given routine rehabilitation therapy combined with respiratory training.On the basis of the control group, the observation group was treated with water therapy.The indexes of lung function, motor function, lower limb muscle tension, function evaluation and activities of daily living were compared between the two groups.Results:After intervention, the observation group′s forced vital capacity (FVC) was (3.86±0.82) L, the forced expiratory volume in the first second (FEV1) was (3.76±0.68) L, the maximum ventilation (MVV) was (102.34±10.38) L/min, the maximum suction pressure (MIP) is (50.36±4.62) cmH 2O; the control group FVC was (3.41±0.76) L, and FEV1 was ( 3.35±0.63) L, MVV was (90.67±11.68) L/min, MIP was (44.38±4.85) cmH 2O, the difference between the two groups is statistically significant ( t=2.546, 2.797, 4.723, 5.646, respectively, all P<0.05). After the intervention, the motor function score of the american spinal injury association (ASIA) of the observation group was (58.62±7.56) points, and the modified ashworth scale (MAS) score was (2.74±0.89) points; The ASIA motor function score of the control group was (42.24±6.40) points, and the MAS score was (3.36±0.94) points.The difference between the two groups was statistically significant ( t=10.459 and -3.029, respectively, all P<0.05). After intervention, the observation group′s spinal cord independence measure (SCIM III) score was (75.33±10.72) points, and the modified barthel index (MBI) was (66.64±6.34) points; the SCIM III score of the control group was (68.34±9.55) points, and the MBI score was (57.52±6.77) points, the difference between the two groups was statistically significant ( t=3.079 and 6.219, respectively, all P<0.05). Conclusion:Hydrotherapy combined with breathing training can significantly improve lung function and respiratory muscle strength in patients with thoracolumbar spinal cord injury, and improve motor function and ability of daily living.