The invention discloses a smart atomization water supplementing system suitable for a CRTS 3 type pre-tensioned track board. The system comprises a master control cabinet, a control valve, an ultrasonic atomizer, an atomization controller, a heating water tank, a filter, a water inlet valve, a temperature sensor and a humidity sensor, wherein the master control cabinet is used for analyzing data obtained by measurement of the temperature sensor and the humidity sensor, and commanding the atomization controller; the atomization controller is used for further controlling the heating water tank and the control valve; a water inlet of the heating water tank is connected with a tap water pipe by the water inlet valve, and a water outlet of the heating water tank is connected with the control valve; the control valve is connected with one end of the filter by a water pipe, and the other end of the filter is connected with the ultrasonic atomizer; the ultrasonic atomizer is used for transforming water into water mist by means of vibration, and introducing the water mist into a pedestal of the track board through a mist guide pipeline. After the smart atomization water supplementing system is adopted, the maintenance time is effectively shortened; after the track board is supplemented with water, a track board body is good in strength stability; therefore, the production efficiency is greatly improved.