Traditionally, low-grade and low-elongation ductile nodular iron is the major material used for wind power castings. With the rapid development of the times, high elongation is required for wind power castings. This paper principally focused on the material QT500-14 as the research target, employing MAGMA simulation software to devise the casting process for wind power suspension beam castings and optimizing the process through the addition of chills. After dissection and ultrasonic testing, the internal shrinkage porosity and shrinkage hole defects of the casting fulfil the technical criteria. By optimizing crucial elements such as C, Si and Mn, both the metallographic and mechanical properties satisfy the technical criteria, thereby successfully developing the QT500-14 ductile iron wind power suspension beam.