Under the background of emerging engineering education, which is a higher requirement for civil engineering students" professional practical ability, and subject competition is one of the important ways to cultivate students" professional practical ability. According to the requirements of the new engineering course for college students" professional practice ability, aiming at the shortcomings of the current professional practice teaching, relying on the subject competition, the teaching method of "empowering by competition and promoting teaching by competition" is put forward. Taking the national college students" structural design information technology competition as an example, this paper explores the process of cultivating college students" professional practice ability by competitive empowerment from three stages: model establishment, model deepening and model analysis. By participating in the subject competition, students can apply and extend what they have learned in class in the competition, so as to improve their basic practical ability and engineering practical ability. From two aspects of professional courses and practical courses, this paper analyzes the promotion effect and realization way of subject competition on teachers" professional practice teaching. The integration of subject competition and teaching, combining with professional course teaching, improving teaching methods, updating teaching content and forming teaching team based on competition; Combined with practical course teaching, the competition is integrated with production practice, teaching experiment and graduation design to improve teachers" professional practical teaching level. Relying on the teaching platform of Southwest Jiaotong University, the teaching method of "empowering by competition and promoting teaching by competition" has been practiced in the cultivation of college students" professional practical ability, and achieved good results, which can provide reference for the professional practical teaching of civil engineering.