Saalt of a strong acid and base does not hydrolyse because neither the cations nor the anion undergoes hydrolysis. Therefore, the solution remains neutral. 

For example: in the aqueous solution of NaCl, its ions Na⁺ and Cl^– ions have no tendency to react with H⁺ or OH^– ions of water. This is because the possible products of such reaction are NaOH and HCl, which are they completely dissociated. As a result, there is no change in the concentration of H⁺ and OH^– ions and hence the solution continues to remain neutral.