honor student; model student; prize pupil
Refers to a student with excellent grades and conduct, often used in school contexts. Can also be used figuratively for someone who follows rules perfectly.
She is the top honor student in the class.
People who are the model-student type can sometimes be inflexible.
He always plays the model student in front of the teacher.
She is known as the model student of the class.
You don't have to act so much like a model student.