Abstract: Adam Smith's theory of property rights is the intersection of his economic, ethical, and legal ideas, revealing the inherent relationship between human pursuit of profit and the stability of commercial social order. This article is based on the perspective of intellectual history, systematically examining Smith's critical inheritance of modern natural law tradition and Scottish Enlightenment thought, and demonstrating how his private law system centered on property rights laid the foundation for the economic, moral, and legal order of modern commercial society. Research has found that Smith reconstructed the theory of natural rights, shifting property rights from contract theory to labor value theory, and shaping justice rules with the theory of "unbiased observer". Ultimately, he established an institutional link between property rights protection and national wealth growth, providing theoretical support for the legal framework of modern civilized society.