Teachers' professional knowledge mainly includes ontological knowledge, conditional knowledge, practical knowledge and operational knowledge.

1. Ontology knowledge refers to the specific subject knowledge that teachers should possess.

2. Conditional knowledge, teachers should have psychological knowledge such as pedagogy and psychology.

3. Practical knowledge mainly refers to the knowledge and ability that teachers should have in classroom situational teaching and the relevant code of conduct.

4. Operational knowledge refers to teachers' accumulation of teaching experience and knowledge.