Trans-spinal focused ultrasound (tsFUS) is a relatively new noninvasive neuromodulation approach that modulates spinal reflexes in healthy rats. Here, we tested the analgesic efficacy of tsFUS in rats with chronic constriction injury (CCI). Male rats were subjected to CCI of the left sciatic nerve, and a day later were treated with either sham stimulation or tsFUS (2KHz pulse repetition frequency, targeting spinal level L5, 3 minutes per day) for 3 days. We found that CCI increases sensitivity to mechanical stimuli, indicated by a reduced von Frey Threshold (vFT). Compared to sham stimulation, tsFUS resulted increased vFT at 4 to 23 days after CCI, compared to sham stimulation, indicating reduced sensitivity to mechanical stimuli in a sustained manner. In animals that received tsFUS, we found reduced counts of spinal microglia and reduced counts of microglia expressing CD86, a marker for pro-inflammatory microglial activation, at the side ipsilateral to injury. Our study provides evidence that tsFUS may be effective in mitigating early development of pain after neural injury, in part by suppressing the activation of pro-inflammatory phenotypes of spinal microglia.