Objective To explore the effects of high-intensity focused ultrasound (HIFU) on immune function and survival time in rats with cervical cancer. Methods Sixty female Wistar rats were randomly divided into control, model, and HIFU groups, with 20 rats per group. In the model and HIFU groups, human cervical cancer HeLa cells were subcutaneously injected into the left axilla to establish cervical cancer xenograft models. After modeling, the HIFU group underwent local HIFU treatment. The single-point and single treatment time was 10 s for 250 s. After treatment, 10 rats were randomly selected from each group to observe changes in survival time and weight within 9 weeks after model induction. The remaining 10 rats in each group were sacrificed 14 d after treatment. The volume and weight of xenografts in each group were calculated. MTT was applied to detect the vitality of spleen lymphocytes. The apoptosis of peripheral blood T lymphocyte subsets and T lymphocytes was analyzed by flow cytometry. The histopathological changes of xenografts tissues were observed by HE staining. Results Compared with the control group, at 3, 5, and 7 weeks after modeling, rat body weight was significantly decreased in the model and HIFU groups (P<0. 05); the vitality of spleen lymphocytes, peripheral blood CD4⁺ T cells and CD8⁺ T cells, and CD4⁺ / CD8⁺ T cells was significantly decreased (P<0. 05); and the apoptosis rate of T lymphocytes was significantly increased (P<0. 05). Compared with the model group, the median survival time in the HIFU group was significantly prolonged [(54. 51±3. 16) vs (48. 03±1. 05), log rank (χ² )= 7. 504, P = 0. 006]. At 3, 5, and 7 weeks after model induction, the weight of rats was significantly increased (P<0. 05); tumor volume and mass were significantly decreased (P<0. 05); vitality of spleen lymphocytes, peripheral blood CD4⁺ T cells and CD8⁺ T cells, and CD4⁺ / CD8⁺ T cells were significantly increased (P<0. 05); and the apoptosis rate of T lymphocyte was significantly reduced compared with (P<0. 05). Conclusions HIFU can improve the immune function of rats and prolong the survival time of rats with cervical cancer.