Objectives. To explore effectiveness and mechanisms of electroacupuncture (EA) add-on treatment in Parkinson's disease (PD) patients. Methods. Fifty PD patients were randomly assigned to drug plus EA (D + EA) group and drug alone (D) group. Subjects in D + EA group received stimulation in points of bilateral fengfu, fengchi, hegu, and central dazhui. Participants were evaluated by scales for motor and nonmotor symptoms. Levels of neuroinflammatory factors and neurotransmitters in serum were detected. Results. EA add-on treatment remarkably reduced scores of Unified Parkinson's Disease Rating Scale (UPDRS) III and its subitems of tremor, rigidity, and bradykinesia and conspicuously decreased UPDRS III scores in patients with bradykinesia-rigidity and mixed types and mild severity. Depression and sleep disturbances were eased, which were reflected by decreased scores of Hamilton Depression Rating Scale, Pittsburgh Sleep Quality Index, and elevated noradrenaline level. Effects of EA add-on treatment on motor symptoms and sleep disturbances were superior to drug alone treatment, markedly improving life quality of PD patients. EA add-on treatment decreased nitric oxide level in serum. Conclusions. EA add-on treatment is effective on most motor symptoms and some nonmotor symptoms and is particularly efficacious in PD patients at early stage. Antineuroinflammation may be a mechanism of EA add-on treatment.