Audiovisual conflict control is an important cognitive function in humans. However, it was not clear whether there was a defect in audiovisual conflict control in Parkinson’s disease (PD) patients, nor was it clear how it was reflected at periods of perception and response in the cognitive process. We recruited 27 PD patients and 22 healthy controls (HC) to complete audiovisual matching task to investigate the audiovisual conflict in PD patients at different processing periods and its relationship with cortical thickness. Behavioral results showed that HC group showed stronger visual interference at both periods of perception and response. But in PD patients, there was no significant difference between visual interference and auditory interference at period of perception, indicating the abnormal audiovisual conflict. In addition, the cortical thickness of left middle frontal gyrus (MFG) in PD patients was positively correlated with the sensory interference (visual interference > auditory interference) at period of perception, and the thinner the left MFG was, the weaker sensory interference was. The abnormal audiovisual conflict in PD patients was reflected at period of perception, and was associated with the cortical thickness of the left MFG, revealing the important role of the left MFG in conflict control in PD patients.