The utility model discloses a fruit juice hot filling device which comprises a filling machine; the inlet of the filling machine is connected with a three-way valve connected with a controller; the controller can control the switching motion of the three-way valve; the other two ends of the three-way valve are respectively connected with a buffer tank and the first outlet of a second heat exchanger; a pipeline between the three-way valve and the second heat exchanger is provided with a numerical control temperature meter; the numerical control temperature meter is connected with the controller; the buffer tank is connected with a conveying pump; the conveying pump is connected with the first inlet of a first heat exchanger; the first outlet of the first heat exchanger is connected with the first inlet of the second heat exchanger; the second inlet of the second heat exchanger is connected with a steam pipeline; the second outlet of the second heat exchanger is connected with the second inlet of the first heat exchanger; the second outlet of the first heat exchanger is connected with a dewatering valve. The fruit juice hot filling device provided by the utility model guarantees the fruit juice sterilizing effect, effectively improves the steam heat exchange efficiency, and lowers the energy consumption.