Objective To analyze the preventive effect of lower limb rehabilitation robot combined with intermittent pneumatic compression device (IPC) on lower limb deep vein thrombosis (DVT) in patients with limb motor dysfunction after brain injury. Methods A total of 90 patients with limb motor dysfunction after brain injury admitted to Beijing Rehabilitation Hospital Affiliated to Capital Medical University from December 2020 to December 2021 were studied by convenience sampling method. According to different treatment methods, they were divided into 2 groups with 45 cases in each group. The control group was given routine rehabilitation training and IPC treatment. The observation group was given lower limb rehabilitation robot treatment on the basis of the control group, and the two groups were evaluated 3 months after treatment. The clinical efficacy, National Institutes of Health Stroke Scale (NIHSS) score, modified Barthel index (MBI) score, coagulation and fibrinolytic system index, lower limb deep venous blood flow mechanical parameters, and the incidence of DVT were compared between the two groups. Results The total effective rate of observation group (95.56%) was higher than that of control group (75.56%) (P＜0.05) After treatment, NIHSS score of observation group was lower than that of control group (P＜0.05), and MBI score of observation group was higher than that of control group (P＜0.05) The D-dimer (D-D) and fibrin degradation product (FDP) of observation group after treatment were lower than those of control group, and the thrombin time (APTT) and prothrombin time (PT) of observation group after treatment were higher than those of control group (P＜0.05) After treatment, the mean blood flow velocity (Vm) of popliteal vein, femoral vein and external iliac vein in the observation group was higher than that in the control group (P＜0.05)The incidence of DVT in observation group (2.22%) was lower than that in control group (15.56%) (P＜0.05)Conclusion Lower limb rehabilitation robot combined with IPC can effectively improve the nerve function and lower limb blood flow velocity of patients with limb motor dysfunction after brain injury, improve daily living ability, correct blood hypercoagulability, and reduce the incidence of DVT, which is worth learning