CAD-based clothing design is known for its ease and flexibility, yet it often lacks intuitiveness and requires extensive experience for successful garment creation. To address these limitations, this paper presents a novel modular virtual interactive clothing design system using OpenGL and 3D modeling technologies. This system employs virtual reality to enable three-dimensional interactions, creating 3D garments that are then mapped onto a 2D plane for further evaluation. The evaluation module assesses the garment’s balance, line coherence, looseness, and wrinkle aesthetics to finalize the design. The research demonstrates that design discrepancies are kept below 1% in this virtual setting. The system’s modular nature also ensures satisfactory garment fit and appearance, underscoring its practical significance and potential impact.