Under the digitalization of big data information, the traditional way of teaching botany courses faces challenges and opportunities, and using big data technology to improve the quality of botany teaching becomes a key research problem. Firstly, based on the big data technology and the teaching objectives of botany in colleges and universities, the teaching system platform is proposed to be constructed by a discrete regression algorithm and Hadoop platform. Then the structure and functions of the teaching system are designed according to the needs of teachers and students and course objectives, and the teaching system is realized for practical application in botany courses. Finally, starting from students as learning subjects, biological engineering students of Guizhou University were identified as the research objects, and the teaching system platform based on the discrete regression algorithm was used to conduct weight analysis on the teaching of botany courses in colleges and universities. The results showed that the mean values of the botany course, bacteriology course, zoology course and microbiology weight were 25.64%, 25.32%, 24.57% and 24.47%, respectively, and the overall weight means performance showed that botany was better than the other three types of biology courses with the mean value of 25.64%. This study has helped improve botany teaching quality and curriculum reform by increasing the participation of students in classroom teaching.