壓鑄是工業中應用極為廣泛而重要製造方法之一,但作業環境因其高熱、高噪音而常令人感到屬於危險、辛苦、骯髒的3K工作。所以較少人願意投身其中,而其相關研究大多見於學術上。在壓鑄製程中最重要的關鍵之一為其模具壽命的延長,而模具壽命的長短攸關整體產能與品質甚為巨大。本論文研究了雷射焊補的技術延長模具壽命,且在微觀組織當中探討了模具發展熱龜裂的主因與為何模具經過雷射焊補後延緩熱龜裂的發生,最後運用了CAE技術探討發生熱龜裂發生的高風險區域。;High pressure die-casting is one of the most widely used and important manufacturing method in modern industry, but the working environment is often dangerous, hard and dirty due to its high temperature and high noise. This is the reason why fewer people are willing to devote themselves to the job, and furthermore, most of researches about high pressure die-casting is academic study. One of the most important problem in the die-casting process is die service life improvement, and the problem affects not only capacity of production but also quality. In this paper, die- casting die service life improvement by laser-remelting process is investigated. In the view of microstructure, the main cause of thermal fatigue crack of die-casting die and inhibiting the propagation of the crack is discussed. Finally, finding the high-risk region where thermal fatigue crack occurs is worked out by the application of CAE(Computer Aided Engineering) technology.