In view of the status of shortage in innovation ability cultivation in Chinese doctoral education, the authors analysed the cultivation mode of innovation ability of American doctoral students through the visiting opportunity to University of Cincinnati. The paper did comparative analysis of training mode between Chinese and American doctoral students, including the quality of enrollment, training process, psychological adjustment and occupation planning.Based on the training experience of innovation ability of American doctoral students, we put forward some suggestions, including providing guarantee for their scientific research in daily life,improving the enrollment mode, promoting the two wheel drive of course papers, providing innovation environment and cultural construction for personnel training,establishing tutorial groups, serving for doctoral students' personalized demands, paying attention to psychological adjustment and occupation planning. This investigation will further advance the reform of training model of doctoral students in engineering in China. Finally, it will lay the cornerstone for improvement of the country's overall innovation ability.