Abstract: In 1941, with yearning for Dunhuang and persistence in art, ZHANG Da-qian overcame various difficulties and carried out activities in Dunhuan, as numbering rock caves, collecting and sorting out text data, and copying fresco. While his painting skills tended to be mature and he got close knowledge of ancient Chinese culture, he made clear the line of Chinese art, which endowed the vitality to his lotus painting in both technique and spirit. From ZHANG’s art experience, we can find his journey to Dunhuan for nearly three years was the main drive for his painting’s change from elegance in his middle age to grandeur. And Da-qian’s technique of lotus painting began to be perfect and his art style was hence promoted.