Disclosed are a method and system for measuring leakage area for construction of smoke control equipment. The invention provides a system for measuring a leakage area of a test room that can include: a chamber positioned in the test room and storing air compressed by a compressor; one or more pressure sensors configured to measure a pressure change of the test room when the compressed air in the chamber is discharged instantaneously; and a gauging means configured to measure an effective leakage area in the test room by using a pressure change value of the test room detected by the one or more pressure sensors. Embodiments of the invention can enable an accurate measurement of leakage area at low cost.