The invention discloses an instant-heating anti-electrical wall water heater, which comprises an outer bottom casing, a water inlet and outlet insulating tube which is installed on the outer bottom casing, a heating cap, a control circuit, and a thermoregulator, a water-flow regulating valve and a pressure switch which are arranged on the water inlet insulating tube. The invention is characterized in that the thermoregulator comprises an auto-reset thermoregulator which can keep outlet water in constant temperature and is controlled by water temperature, and a manual reset thermoregulator which is manually controlled to monitor the water heater. An insulating mechanism which leads the length of the inlet and outlet watercourse in the tube longer than the actual length of the water inlet and outlet insulating tube is arranged in the water inlet and outlet insulating tube, a spiral rod which takes screw bolt shape in a screw conveyer is arranged in the water inlet and outlet insulating tube, which leads the watercourse to form a spiral connecting watercourse in the tube, or a rotative surface twist strip which is twisted and coiled by a twist plate of a plastic flake is arranged in the water inlet and outlet insulating tube. The invention has simple structure, good hidden effect, simple and convenient employment, which cannot increase manufacture cost and service space, and inconvenience and electroshock hidden danger which is caused by improper installation can be eliminated when the water heater is installed by the user.