The nutritional composition of pear juice, including its flavor profile and bioactive compounds, plays a pivotal role in determining its quality and is significantly influenced by the pear cultivar. This study assessed key flavor compounds, including sugars, organic acids, and volatiles, as well as antioxidant properties (mainly consisting of phenolics, 1,1-diphenyl-2-picrylhydrazyl radical, and hydroxyl radical scavenging activity) and sensory attributes based on electronic tongue and nose technologies, of pear juices across 20 cultivars from four pear species. The results demonstrated a consistent relationship between flavor compounds and sensory attributes. The total sugar content was positively associated with sweetness perception, with Pyrus bretschneideri, Pyrus pyrifolia, and Pyrus sinkiangensis exhibiting higher sugar levels than Pyrus ussuriensis. Similarly, total organic acid content corresponded to sourness perception, following the trend: P. ussuriensis > P. bretschneideri > P. pyrifolia and P. sinkiangensis. Notably, P. ussuriensis juices displayed higher levels of total volatile compounds, especially for esters, as confirmed by electronic nose analysis identifying a distinct volatile profile for this species. Additionally, principal component analysis highlighted that P. ussuriensis juices were characterized by higher levels of total acids, citric acid, malic acid, esters, and antioxidant properties, along with reduced total sugars, glucose, and fructose levels. Partial least squares-discriminant analysis further screened ten differential variables contributing to group differentiation. These results indicated P. ussuriensis juices possessed distinctive characteristics of higher sourness, lower sweetness, rich aroma, and potential health benefits, which will provide foundational information to support the development of the pear juice industry in China.