School physical education is an ideal place to improve the physical fitness of young people. In China, school physical education includes physical education and health education. Physical education teacher is an important factor that influences the quality of school physical education. This study was based on the government policy of “deepening the comprehensive reform in the field of education”. The purposes were to investigating the current situation of Chinese physical education teachers’ teaching, providing suggestions and directions for the improvement of their teaching, and subsequently improving students’ physical health. This study adopted the following methods: literature review, questionnaire and interview methods. The participants of this study were physical education teachers who were recruited through random sampling across the country. Interview and questionnaires were conducted at three occasions: before class, during class, and after class. In-depth quantitative and qualitative analyses were conducted to understand the cognition and teaching status of physical education teachers. Data analysis results showed that teachers’ academic qualifications was positively correlated with their understanding of theoretical knowledge such as curriculum standards (p < 0.05, r = 0.468). For class implementation, only about 23.3% teachers’ teaching practice met the requirement of China’s healthy physical education curriculum model in term of the amount of physical activity. There was a significant difference between the length of teaching and the curriculum arrangement (p < 0.01). Finally, for after-school activities, the organization of after-school physical activities was mainly focusing on sport practices, and varsity team training accounted for 61% of these sport practices. Many different types of reasons were raised by the teacher about the factors restricting physical exercise after school. Under the background of policies advocating the integration of sports and education, it is important to raise the professional standards of being a physical education teacher. Current physical education teachers should learn how to implement the “Chinese Health Sports Curriculum Model”. More professional development opportunities should be provided for physical education teachers in terms of teaching methods, curriculum development, and after-school physical activity program development. Physical education teachers should learn the factors that restricts students from participating in after-school physical activities and the strategies to address these restricting factors.