In order to respond to the construction of first-class undergraduate majors,improve the teaching quality of Biochemistry Experiment course,and improve the students'independent learning ability,practical ability and scientific research ability,the PBL teaching mode was designed and practiced for 378 students of grade 2020 in four majors of the college.In the process of experimental teaching,by organically integrating the information technology and PBL teaching methods,situational problems were set,and the teaching system was constructed and implemented for the three links:pre class,in class and after class.The results showed that this teaching mode could significantly improve the teaching effect,improve the students'independent self-study ability and cooperative practice ability,help to cultivate the students'independent scientific research ability,and serve the construction of first-class undergraduate majors.