Objective To investigate the depressive state of patients with Parkinson's disease (PD), and to analyze the correlation of depressive state with autonomic dysfunction. Methods A total of 327 patients with PD in the hospital were selected from March 2022 to March 2024. The depressive state was evaluated by Hamilton Depression Scale (HAMD). The autonomic nerve function was assessed using the Scale for Outcomes in PD for Autonomic Symptoms (SCOPA-AUT) and heart rate variability [standard deviation of sinus RR interval (SDNN), standard deviation of average sinus RR interval (SDANN), and percentage of successive NN interval differences above 50 ms (pNN50)]. According to the positive depression (HAMD>20 points), the patients were divided into a depression group and a non-depression group. The clinical data and autonomic nerve function indicators were compared between the two groups. Pearson correlation coefficient analysis was performed to analyze the correlation between depressive state and autonomic dysfunction in PD patients. Results The positive rate of depression in patients with PD was 31.19%. There were 102 patients in the depression group and 225 patients in the non-depression group. The years of education and the proportion of mild Hoehn-Yahr stage (H-Y stage) in the depression group were lower than those in the non-depression group, while the disease course was longer, and the Unified Parkinson's Disease Rating Scale (UPDRS) II score and UPDRS III score were higher than those in the non-depression group (P<0.05). The SCOPA-AUT score in the depression group was higher while the SDNN, SDANN and pNN50 were lower compared to the non-depression group (P<0.05). HAMD score was positively correlated with SCOPA-AUT score (r=0.685), and was negatively correlated with SDNN, SDANN and pNN50 (r=-0.578, -0.685, and -0.439) (P<0.05). Conclusion Depression is a common state among patients with PD, and its level is positively correlated with the severity of autonomic dysfunction in patients.