The invention relates to a high-frequency induction fluid heater which comprises a tank, an upper flange plate, a lower flange plate, a plurality of graphite nodules, an upper barrier, a lower barrier, an induction coil, a plurality of thermocouples and a high-frequency induction generator. The tank is provided with an inlet flange plate and an outlet flange plate, the inlet flange plate is arranged at an inlet end of the bottom of the tank, and the outlet flange plate is arranged at an outlet end of the top of the tank; the upper flange plate is hermetically connected with the outlet flange plate; the lower flange plate is hermetically connected with the inlet flange plate; the graphite nodules are arranged inside the tank; the upper barrier is arranged inside the tank and is positioned above the graphite nodules, and a plurality of upper flow guide holes are arranged on the surface of the upper barrier; the lower barrier is arranged inside the tank and is positioned below the graphite nodules, and a plurality of lower flow guide holes are arranged on the surface of the lower barrier; the induction coil is wound in the middle of the outer edge of the tank; the thermocouples extend into the tank from the upper side of the upper flange plate; and the high-frequency induction generator is connected with the induction coil and the thermocouples. The high-frequency induction fluid heater has the advantages of good thermal shock resistance, high corrosion resistance, stability in heating performance, long service life of equipment, and the like.