Internet +" has brought unprecedented changes to the education sector, and pigai.org is widely used by colleges and universities as an automatic online correction system for English essays. In the field of education, formative assessment is becoming popular as a new assessment method. Based on the background of the times and teaching reform, this study innovatively combines the "Internet+" teaching environment with formative assessment and applies it to college English writing teaching, constructs the "Internet+" college English writing formative assessment model and tests it empirically. The model of "Internet+" formative assessment of college English writing is constructed and empirically tested, aiming to provide a solution to the current problems in college English writing teaching.