Soluble sugars, primarily fructose, glucose, sucrose, and sorbitol, are crucial determinants of fruit flavor and quality. As a core component of biological metabolism, sugar metabolism provides energy and carbon for fruit development, ultimately governing carbohydrate accumulation in mature fruits. This process requires the coordinated activities of multiple enzymes and transporters, modulated by the spatiotemporal expression patterns of their encoding genes. Therefore, it is essential to elucidate both the activities of these enzymes across different fruits and their underlying gene expression patterns. While significant progress has been made in functional genes involved in soluble sugar metabolism and deciphering their regulatory networks, an overall introduction of this knowledge remains lacking. This review presents an integrative analysis of soluble sugar accumulation during fruit development, encompassing spatiotemporal dynamics of key metabolic enzymes, functional characterization of encoding genes, signaling response mechanisms governing gene regulation, and the overarching genetic network.