Parkinson's disease (PD) is a common neurodegenerative disorder. Early symptoms are often subtle, and by the time of diagnosis, patients typically exhibit significant motor and non-motor impairments. Currently, there is a lack of specific tests for early PD diagnosis or prognostic evaluation, underscoring the urgent need to identify biomarkers that can elucidate the underlying mechanisms of PD. This paper mainly reviews the expression of markers such as α-Synuclein (α-Syn), YKL-40, neurofilament light chain (NfL), amyloid β (Aβ) 1-42, and Tau protein in the cerebrospinal fluid or blood of patients with PD. Additionally, it summarizes the different roles of inflammatory factors such as interleukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor-α (TNF-α) in PD-related cognitive dysfunction. By exploring the dynamic changes in these biomarkers, new avenues may emerge for early PD diagnosis and prognosis prediction.