Based on dynamic theory of liquid crystal and finite-difference iterative method, dynamic response of strong anchoring hybrid aligned nematic (HAN) liquid crystal cell as removing applied voltage was studied. Flexoelectricity of liquid crystal material was considered. Time-dependences of transmittance through a HAN cell were obtained. It indicates that response time decreases with increasing of absolute value of the sum of splay and bend flexoelectric coefficient |e₁₁+e₃₃|. Especially, at |e₁₁+e₃₃|=50 pC·m^-1 response time is half shortened relative to the case with no flexoelectric effect.