Science data literacy (SDL) is an important literacy for college students in STEM majors to possess. However, the current understanding of SDL is incomplete and lacks effective cultivation strategies. This study integrates the core ideas of science literacy (SL) and data literacy (DL), while considering the characteristics of science data, and constructs a conceptual framework of SDL that contains three dimensions. The Delphi method was used to further optimize this framework. The WorldWide Telescope (WWT), as a visual exploration platform centered on astronomical data, integrates a large amount of astronomical science data, which provides the possibility of cultivating students' SDL. Based on the optimized SDL conceptual framework and WWT software, we designed a curriculum for college students majoring in STEM and practiced it for 4 weeks. The practical results show that the course is effective in developing students' SDL. This study helps to deepen the connotation of SDL and also provides new ideas for cultivating SDL for college students majoring in STEM.