A method and apparatus for determining a water chilling unit for cooling a data center are provided. The method includes: acquiring a current water output parameter, a current water input parameter, a current water flow parameter and a current outdoor temperature parameter of each water chilling unit of the data center; pre-processing the water output parameter, the water input parameter, the water flow parameter and the outdoor temperature parameter to obtain a characteristic parameter of each water chilling unit; importing the characteristic parameters of each water chilling unit into a pre-established machine learning model to obtain the current electric power of each water chilling unit; and determining a water chilling unit for cooling the data center on the basis of a preset cooling load, a rated cooling capacity of the water chilling unit and the current electric power of each water chilling unit.