Objective To investigate the correlation between uroflowmetry and motor function， cognitive function in patients with Parkinson disease （PD）， multiple system atrophy （MSA） and progressive supranuclear palsy （PSP）. Methods A total of 27 PD patients， 17 MSA patients， and 16 PSP patients who visited the Department of Neurology， Guangdong Provincial People's Hospital from December 2018 to December 2021 were selected. The demographic data of the patients were recorded. The overall cognitive function of the three groups was assessed and compared using the Montreal Cognitive Assessment （MoCA） and Mini-Mental State Examinationl （MMSE）. The motor function of the three groups was assessed and compared using the HoehnYahr （H-Y） and Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale Ⅲ （MDS-UPDRS Ⅲ）. The uroflowmetry of the patients was assessed using an intelligent urodynamic tester. Spearman correlation was used to analyze the correlation between cognition， motor function and uroflowmetry in three groups. Results The course of disease in PD group was 4.0 （2.0，7.0） years， which was longer than 2.0 （1.0， 2.5） years in MSA group， and the difference was statistically significant （H=-16.038，P ＜ 0.01）. There was no statistical difference in MDS-UPDRS Ⅲ， MoCA and MMSE scores among the 3 groups （P＞ 0.05）. The H-Y score of PD group was 2.5 （2.0， 3.0）， which was lower than 3.0 （2.5， 3.0） of PSP group， and the difference was statistically significant （H=-14.683， P＜ 0.05）. There was a statistically significant difference in urination delay time among the three groups （H=6.196， P ＜ 0.05）. Further Spearman correlation analysis showed that MDS-UPDRS Ⅲ score in PD group was positively correlated with the time to reach the maximum uroflowmetry （r=0.379， P=0.047）； MMSE score was negatively correlated with the maximum uroflowmetry， mean uroflowmetry and urinary flow acceleration （r=-0.419，-0.456，-0.402； P＜ 0.05）； MoCA score was negatively correlated with maximum uroflowmetry， mean uroflowmetry， urine output and urinary flow acceleration （r= -0.427，-0.432，-0.384，-0.385； P＜ 0.05）. In MSA group， MDS-UPDRS Ⅲ score was negatively correlated with maximum uroflowmetry and urinary flow acceleration （r=-0.527，-0.696； P ＜ 0.05）， and positively correlated with total voiding time （r=0.619，P ＜ 0.05）； MMSE score was positively correlated with time to achieve maximum uroflowmetry （r=0.499， P ＜ 0.05）. In PSP group， MDS-UPDRS Ⅲ score was positively correlated with time to achieve maximum uroflowmetry （r=0.549，P ＜ 0.05）， and negatively correlated with urinary flow acceleration （r=-0.621， P＜0.05）. Conclusions There is no significant difference in uroflowmetry among PD， MSA and PSP patients. Urinary acceleration is negatively correlated with motor function， maximum uroflowmetry is positively correlated with cognitive function in PD patients， and mean uroflowmetry is positively correlated with cognitive function in MSA patients.