Objective To explore the characteristics of facial emotion recognition function impairment in PD patients, and the correlation between emotion recognition and P300 latency and amplitude through the detection of facial emotion recognition function and event-related potential P300 in non demented Parkinson disease (PD) patients. Methods A total of 28 cases of early non-dementia PD patients (PD group) and 32 cases of healthy physical examination (HC group) were selected. The eye area emotion recognition test and P300 test were applied to observe the recognition scores of the six basic emotions (joy, surprise, terror, sorrow, disgust and anger), as well as P300 latency and amplitude. The correlation of the six emotion recognition scores with the P300 latency and amplitude were compared. Results Compared with the HC group, the scores of the emotional face recognition of the “terror”, “sorrow” and “disgust” in the PD group were lower than those in the control group (P < 0.05); P300 latency in PD group was prolonged (P < 0.05), and amplitude was decreased (P < 0.05); P300 latency were negatively correlated with “terror” (r = -0.718, P < 0.05), “sorrow “(r = -0.614, P < 0.05), “disgust” (r = -0.818, P < 0.05), “angry” (r = - 0.829, P < 0.05) scores , and P300 amplitude were positively correlated with “sorrow” (r = 0.824, P < 0.05), “disgust” (r = 0.928, P < 0.05), and “angry” (r = 0.621, P < 0.05) scores. Conclusions PD patients have damage in the eye area emotional cognition, and impairment of the face emotion recognition are mainly based on “terror”, “sorrow” and “disgust” negative facial emotions, further confirming the hypothesis that the basal ganglia participates in emotional cognition processing; P300 and face emotion recognition scores have good correlation, and P300 latency and amplitude are reflected as sensitive indicators for emotional cognitive impairment of early Parkinson disease patients without dementia.