Objective To investigate the correlation of blood flow parameters and serum human nuclear transcription factor peptide p65 (NF-κBp65) level with conservative treatment of uterine fibroids by transvaginal ultrasound. Methods The clinical data of 148 patients with uterine fibroids who received conservative treatment in our hospital from April 2023 to December 2023 were retrospectively collected. According to the effect of conservative treatment, the patients were divided into effective group (114 cases) and ineffective group (34 cases). Blood flow parameters (pulse index (PI), end-diastolic flow rate (EDV), resistance index (RI), peak systolic flow rate (PSV)) and serum NF-κBp65 levels of transvaginal ultrasound were collected and compared between the two groups before and after treatment. The correlation of blood flow parameters and serum NF-κBp65 level with the therapeutic effect of transvaginal ultrasound was analyzed. To analyze the value of transvaginal ultrasound blood flow parameters combined with serum NF-κBp65 level in evaluating the therapeutic effect. Results Before treatment, there were no significant differences in serum NF-κBp65 level, PSV, EDV, RI and PI between the two groups (P > 0.05). Compared with the effective group, RI in the ineffective group after treatment was significantly decreased, serum NF-κBp65 level, PSV, EDV and PI values were significantly increased (P < 0.05). The blood flow parameters PSV, EDV, PI and serum NF-κBp65 levels of transvaginal ultrasound were positively correlated with the therapeutic effect of uterine fibroids, and RI was negatively correlated with it (P < 0.05). The AUC of PSV, EDV, RI, PI and serum NF-κBp65 was 0.855, and the best predictive sensitivity and specificity were 91.18% and 79.82%, respectively. Conclusion The blood flow parameters and serum NF-κBp65 level of transvaginal ultrasound have a certain value in evaluating the treatment effect of uterine fibroids.