Constant-temperature pre-instant-heating liner-in-liner electric water heater

The utility model provides a constant-temperature pre-instant-heating liner-in-liner electric water heater. The constant-temperature pre-instant-heating liner-in-liner electric water heater comprisesa water storage liner and a preheating electric heating tube, an inner container water inlet joint and an inner container water outlet joint are arranged on the water storage inner container; the preheating electric heating tube is arranged in the water storage liner; particularly, the water dispenser further comprises an instant heating device and a water mixing valve. The instant heating devicecomprises an instant heating inner container and an instant heating electric pipe, the instant heating electric pipe is arranged in the instant heating inner container, an instant heating water inletpipe and an instant heating water outlet pipe are arranged on the instant heating inner container, the instant heating device is arranged in the water storage inner container, and the electrode end ofthe instant heating electri