Disclosed is a reinforced composite membrane for water electrolysis, and a membrane electrode assembly having the same. More particularly, the present invention relates to a reinforced composite membrane for water electrolysis, and a membrane electrode assembly (MEA), wherein a two-dimensionally woven fabric base, layer that, minimizes swelling of the membrane in the X-axis and Y-axis directions is covered on a hydrogen electrode to which high pressure is applied or on hydrogen and oxygen electrodes by three-dimensionally electrospun reinforcing fiber layers, the reinforcing fiber layers minimizing swelling of the membrane in the Z-axis direction, thereby reducing permeation of oxygen (O2) via the hydrogen electrode and enabling operation under high pressure due to high dimensional stability.