Abstract [Objective] Quantitative evaluation of EMG changes in patients with facet joint disorders treated by lumbar oblique wrench under various movements. [Method] The surface electromyography was used to test the surface electromyography of the lumbar dorsal muscle of patients with small joint disorder (patient group) and normal people (normal group) before and after the treatment of lumbar oblique wrench. Score in combination with the scale. To analyze the difference of myoelectric activity of lumbodorsal muscle between patients and normal people during exercise, and the prognosis of symptoms and signs of patients. [Result] The VAS score of patients with facet joint disorder after treatment was lower than that before treatment (P<0.05). JOA score of patients with facet joint disorder after treatment was higher than that before treatment (P<0.05). After treatment, the mean amplitude and median frequency of the EMG of the erector spine and multifidus muscles in the patients with facet joint disorders were lower than those before treatment (P<0.05); However, the average amplitude and median frequency of EMG of erector spinalis and multifidus in patients with facet joint disorder after treatment were not significantly different from those of normal people (P>0.05). [Conclusion] Lumbar oblique wrench can relieve pain and promote the recovery of lumbar muscle function in patients with small joint disorders. This study provides scientific theoretical basis for exploring the best treatment strategy.