An air flow control method and system for cooling a data center including a server room is disclosed. The method including receiving a first differential pressure value of an air pressure of a first chamber relative to the air pressure of the outside area; receiving a second differential pressure value of the air pressure of a second chamber relative to the air pressure of the outside area; generating a first control signal to adjust the speed of an inlet fan based on the first differential pressure value; generating a second control signal to adjust an outlet fan speed based on the second differential pressure value; transmitting the control signals to the respective inlet and outlet fans to adjust the first differential pressure value to a first target value, and adjust the second differential pressure value to a second target value.