Does every 3CNF propositional formula has an equisatisfiable 2CNF propositional formula
Yes.  If the 3CNF formula is satisfiable, here is an equisatisfiable 2CNF formula: True.  If the 3CNF formula is not satisfiable, here is an equisatisfiable 2CNF formula: False.  So yes, every 3CNF formula has an equisatisfiable 2CNF formula.

If you want to actually find that formula in a reasonable amount of time, then we don't know of any way to find such a formula in polynomial time (existence of such a method would prove that P = NP).