To analyze the application of upper limb rehabilitation robot assistant therapy in upper limb function rehabilitation of stroke patients with hemiplegia. Methods: Ninety patients with hemiplegia after stroke were randomly divided into the control group and observation group with 45 patients in each group. Both groups received routine rehabilitation training, and the observation group additionally received upper limb rehabilitation robot assistant treatment. The Modified Ashworth Scale (MAS), Fugl-Meyer Assessment of Upper Extremity (FMA-UE), and Function Independent Measure (FIM) scores of the two groups were compared before treatment and one month after treatment. Results: The MAS score of the elbow joint in the observation group decreased significantly one month after treatment compared with that of the control group (P<0.01), and there was no significant difference in control group scores before and after treatment (P>0.05). The MAS score of the shoulder joint in both groups decreased one month after treatment, and furthermore, that of the observation group was decreased compared to the control group (P<0.01). The FMA-UE score of both groups was higher at one month after treatment than before treatment, and that of the observation group was increased compared to the control group (P<0.01). Compared with before treatment, the FIM score in both groups were significantly higher one month after treatment, and that of the observation group was significantly higher compared to the control group (P<0.01). Conclusion: When used in addition to a foundation of routine rehabilitation training, upper limb rehabilitation robot assistant treatment of stroke patients with hemiplegia can effectively improve upper limb motor function and promote motor function recovery.