Objective To observe the effect of ultrasound-guided paraspinal nerve block combined with transcranial direct current stimulation(tDCS)on pain and mood in patients with postherpetic neuralgia. Methods From March 2022 to August 2022, 72 patients with PHN were randomly divided into two groups: The control group (group A, n = 36)and the observation group(group B, n = 36). Both groups were treated with neural nutrients, analgesics and ultrasound-guided paraspinal nerve block. The patients in group B received daily transcranial direct current stimulation, while the patients in group A was treated with sham stimulation. Numerical Rating Scale (NRS)and state-trait anxiety inventory(STAI-S)were assessed at the time of pre-treatment(T0), 1 week(T1), 1 month(T2), 2 months(T3)and 3 months(T4)after treatment, self-rating scale of sleep(SRSS)was assessed at T0, T2, T3 and T4. The therapeutic effects of the two groups were evaluated 3 months after treatment. Results After treatment, the scores of NRS, STAI-S and SRSS in both groups were significantly lower than those before treatment(P < 0.05), the scores of NRS, STAI-S and SRSS in group B were significantly lower than those in group A(P < 0.05). Three months after treatment, the curative effect of group B was better, the difference was statistically significant(P < 0.05). Conclusions Ultrasound-guided paraspinal nerve block combined with transcranial direct current stimulation is more effective than paraspinal nerve block alone in relieving pain, improving mood and sleep quality in patients with postherpetic neuralgia. [ABSTRACT FROM AUTHOR]