Chinese Ying-xing Sung (1587-1663), of the Ming Dynasty, and Italian Leonardo da Vinci (1452-1519), of the Renaissance period, were two celebrated scientists from the East and West. There are numerous research papers on their scientific achievements and artistry but no literature focusing on the differences in their design thinking and graphic expression. Therefore, this paper uses document analysis to compare Ying-xing Sung's Tian-kung Kai-wu and da Vinci's notes, thus helping us understand the similarities and differences in their design thinking and graphic design form. Results show: (1) Both of them use field observations, recording visual experiences and using graphic sketches to offer explanations for natural phenomena, incorporating processes of statistics, quantification, and verification. Their design thinking modes are similar in how they integrate interdisciplinary knowledge and skills, so as to disqualify rumors, doctrine, and superstition, as well as fragments of natural science and empirical research. They also resemble each other in their methodology and execution yet differ in their thought and creative processes.(2)The fields they similarly focus on are machinery, weaponry, gunpowder, engineering, hydromechanics, botany and natural phenomena.(3)Because of differences in their text mining, their graphic design forms and drawing styles vary greatly. We expect this study to serve not only as a medium for interdisciplinary ＂Design Thinking＂ but also as a basis for further research.