He is a student. Here 'he' belongs to subject, 'is' belongs to helping verb and student is an object. But object is something 'being worked upon'. But there is no action verb in this sentence. So what does the student stands for because according to the definition of object, student is not that object of this sentence.
towel teal 701and student is an object.

No. It's called a (subject) complement because 'is' (and other forms of be) is a linking verb. It's not called an object. Here are some more like that:

My sister's name is Laura.
My dog Rex is a spaniel.
Fred and Rita are cousins.

Here 'Laura', 'a spaniel' and 'cousins' are subject complements, not direct objects.