A method for controlling an air conditioner comprising a chilled water circulating system, comprising: determining, according to a historical time, a historical refrigerating capacity and historical outdoor weather parameters corresponding to the historical time, and current outdoor weather parameters, a calculation formula of a current refrigerating capacity prediction value to be: the current refrigerating capacity prediction value = A * load time compensation coefficient * f1; determining a water outlet temperature time compensation value according to the current outdoor weather parameters and a historical water outlet temperature; wherein the step of determining a water outlet temperature time compensation value according to the current outdoor weather parameters and a historical water outlet temperature specifically comprises: acquiring the historical water outlet temperature corresponding to the current outdoor weather parameters; and determining the water outlet temperature time compensation value according to the load time compensation coefficient and the historical water outlet temperature; and determining a temperature control target value according to a reference water outlet temperature or a reference water return temperature and the water outlet temperature time compensation value and a water outlet temperature of a master machine of the air conditioner is controlled through the temperature control target value, wherein A is a constant greater than zero, the load time compensation coefficient is preset according to a current use of a building, and f1 is the historical refrigerating capacity corresponding to the current outdoor weather parameters. determining, according to a historical time, a historical refrigerating capacity and historical outdoor weather parameters corresponding to the historical time, and current outdoor weather parameters, a calculation formula of a current refrigerating capacity prediction value to be: the current refrigerating capacity prediction value = A * load time compensation coefficient * f1; determining a water outlet temperature time compensation value according to the current outdoor weather parameters and a historical water outlet temperature; wherein the step of determining a water outlet temperature time compensation value according to the current outdoor weather parameters and a historical water outlet temperature specifically comprises: acquiring the historical water outlet temperature corresponding to the current outdoor weather parameters; and determining the water outlet temperature time compensation value according to the load time compensation coefficient and the historical water outlet temperature; and determining a temperature control target value according to a reference water outlet temperature or a reference water return temperature and the water outlet temperature time compensation value and a water outlet temperature of a master machine of the air conditioner is controlled through the temperature control target value, wherein A is a constant greater than zero, the load time compensation coefficient is preset according to a current use of a building, and f1 is the historical refrigerating capacity corresponding to the current outdoor weather parameters. acquiring the historical water outlet temperature corresponding to the current outdoor weather parameters; and determining the water outlet temperature time compensation value according to the load time compensation coefficient and the historical water outlet temperature; and determining a temperature control target value according to a reference water outlet temperature or a reference water return temperature and the water outlet temperature time compensation value and a water outlet temperature of a master machine of the air conditioner is controlled through the temperature control target value, wherein A is a constant greater than zero, the load time compensation coefficient is preset according to a current use of a building, and f1 is the historical refrigerating capacity corresponding to the current outdoor weather parameters.