Gray system theory has been used in various disciplines recently, and its potential for language base change analysis and education assessment has been steadily investigated. Grey correlation analysis is a valuable tool for evaluating the effectiveness of instruction, particularly for English majors in colleges and institutions. Optimizing instructional strategies can be achieved through the use of this information. English teaching is profoundly affected by changes in the language bank, which requires teachers to continuously adjust their teaching strategies to adapt to the language’s development trend. Using the dominant correlation degree approach, this study investigates the connection between the changing language pool and the instruction of English majors at colleges and universities.This paper takes 14 colleges and universities of different levels as the investigation object. According to the study, there are no apparent differences between key colleges and ordinary colleges regarding learning needs, but there are differences in teaching requirements and environments. By evaluating the teaching quality of three teachers, it was found that their teaching quality correlations were 0.96, 0.98, and 0.99, respectively, and all reached an excellent level of evaluation. By examining the language bank changes, this study’s gray correlation approach may be improved to enhance the effectiveness and caliber of instruction. The study offers new guidelines for improving English instruction at colleges and universities and an assessment instrument.