［Objective］To reduce defects such as cracking，bending or flaking，and to improve the durability and appearance quality of coating，it is important to investigate generation mechanism andmeasurement methods of internal stress in UV-cured coating，and effects of internal stress on adhesion.［Methods］ The internal stress of coatings with different formulations were measured using thecantilever deflection method，and the relationship between internal stress and coating adhesion strength was studied.［Results］The type of photoinitiator，resin crosslinking density，and selection of reactive diluents significantly influenced the control of internal stress in coatings. Rational formulation designcould effectively reduce internal stress accumulation and enhance coating adhesion. For instance，the TPO initiator could increase crosslinking density and hardness，but its dosage must be controlled to prevent excessive stress. Similarly，there has a optimal dosage of diluents，and the increase of their chain length could reduce internal stress.［Conclusion］ This work provides practical strategies forenhancing the adhesion of UV-cured coatings while minimizing defects.