Abstract: Disclosed is a method for identifying and eliminating ammonium salt deposition characteristics in a pipe of a hydrogenation air cooler. A multiphase flow medium enters an inlet pipe box of a hydrogenation air cooler; cross sections and temperature transmitters are arranged on a pipe bundle of the air cooler in the axial direction; a temperature signal value is monitored and transmitted to a single-chip microcomputer for analysis; an infrared thermal imager performs photographing, and transmits data to determine that an ammonium salt deposition risk is present under this working condition; a monitored temperature value is calculated, an ammonium salt deposition risk identification model is established, and ammonium salt deposits are peeled off from the inner wall of the pipe bundle of the air cooler by means of vibration of the pipe bundle caused by the intermittent frequent switching-on/switching-off of an electromagnet and a magnetic block, and ultrasonic signals.