Objective To observe the influences of electroacupuncture on the levels of polarization markers and inflammatory factors interleukin 6 (IL-6), interleukin 4 (IL-4), tumour necrosis factor-alpha (TNF-α) and interleukin 10 (IL-10) in rats with para-chlorophenylalanine-induced insomnia (PCPA) and to explore the mechanism of action of electroacupuncture in the treatment of insomnia. Methods Fifty healthy SPF grade SD rats, half male and half female, were collected and randomly divided into 10 in the blank group and 40 in the model reserve group, and in the model reserve group, the insomnia rat model was created by intraperitoneal injection of 500 mg/kg PCPA suspension. 30 rats successfully modeled were divided into model group, electro-acupuncture group, and western medicine(estazolam) group, with 10 rats in each group using the random number table method. The western medicine group was given estazolam 0.2 mg/(kg-d) by gavage; the electroacupuncture group was given electroacupuncture of Shenmen, Sanyinjiao and stimulation of Baihui and Benshen acupoints for 20 minutes each once a day, for 7 consecutive days. After treatment, serum and hypothalamic levels of TNF-α, IL-6, IL-4 and IL-10 were detected by ELISA and Western blot; immunofluorescence staining was used to detect the expression of Iba-1 in hypothalamic microglia and the co-expression of its M1 and M2 subtypes of cellular markers, CD86 and CD163 in rats. Results Compared with the blank group, the sleep latency (SL) of rats in the model group was prolonged (P<0.01), the sleep duration (ST) was shortened (P<0.05), the serum and hypothalamus levels of IL-6 and TNF-α and protein levels of rats in the model group were significantly higher (P<0.01), and the levels of IL-4 and IL-10 were lower (P<0.01); compared with the model group, the electroacupuncture group and estazolam group, SL was significantly shorter (P<0.01), ST was prolonged (P<0.01), the serum and hypothalamus levels of IL-6 and TNF-α and protein levels of rats in the electro-acupuncture group and the estazolam group were significantly lower (P<0.01); IL-4 and IL-10 were higher (P<0.01); compared with the western medicine (estazolam) group, IL-6 content in the electroacupuncture group was even lower (P<0.05). Compared with the blank group, Iba-1/CD86 (M1 type) co-expression was significantly enhanced in the model group (P<0.01), and Iba-1/CD163 (M2 type) co-expression was significantly weakened in the model group (P<0.01). After electroacupuncture and western medicine intervention, Iba-1/CD86 co-expression was significantly weakened in the electro-acupuncture group and estazolam group (P<0.01), and Iba-1/CD163 co-expression was significantly enhanced in the model group (P<0.05). Conclusion Electroacupuncture effectively improved sleep disturbances in rats, and its underlying mechanism may be associated with regulating microglial polarization, downregulating the levels of pro-inflammatory cytokines, upregulating the levels of anti-inflammatory cytokines, and alleviating neuroinflammation, thereby ameliorating sleep.