This study investigates the influence of specimen width and thickness on interlaminar edge stress in unnotched tensile specimens of T800-grade carbon fiber-reinforced composite laminates through numerical analysis. The interlaminar stress distribution under tensile loading was simulated for specimens with two thicknesses and three widths using numerical simulation methods. The results indicate that increasing specimen thickness does not exacerbate interlaminar edge stress concentration, which is primarily influenced by the lay-up method. Additionally, moderately increasing specimen width does not effectively reduce interlaminar edge stress; only a substantial increase in width can mitigate this stress. These findings provide analytical support for the development of unnotched tensile testing methods.