In his painting, Haas not only works objectively, but also abstractly. There is often a narrative and poetic inducement, an impulse: a relevant thought to continue to follow, though the direction of thought is completely open. His work is dreamy and fantastic, playful and suggestive. He is influenced by color and surroundings, such as "the northern lights" which he experienced in his travels in Northern Europe, or the earthy colors-rust, ochre, grey and sand found in pictures from Hokes.
On all of his work there is red spot-a stamp-' which is his name in Chinese. Used as a structural element in his compositions, it is also a metaphor for the symbolic stamp that people eventually get characterized in throughout their lives.
Since 1976, Haas has participated in many solo and group exhibitions in Germany and abroad.