The invention discloses a height-adjustable automatic high-pressure mist-spraying device used for fruit tree pollination. The device comprises shifting rollers, a telescopic spray lance and a high-pressure air pump. A base is arranged on the upper portions of the shifting rollers, a pollen liquid tank is arranged on the base, a filter is arranged on the lower portion of the pollen liquid tank, a pollen liquid inlet is formed in the upper surface of the pollen liquid tank, a motor is arranged on one side above the pollen liquid tank, one side of the motor is provided with a draught fan, the high-pressure air pump is arranged on one side of the draught fan, one side of the high-pressure air pump is provided with an electric control valve, and one side of the electric control valve is provided with a power supply switch. The electric control valve is arranged at the bottom of the telescopic spray lance, and a mist-spraying head is arranged at one end of the upper portion of the telescopic spray lance. The device has the advantages that an appropriate high pressure is generated by means of the high-pressure air pump, so that a pollen liquid is sprayed conveniently; the telescopic spray lance is used and can extend to a high place so that flowers on the whole tree crown can be subjected to pollination, a farmer does not need to go up the high place, and the device is convenient to use and high in efficiency.