This paper proposed a novel fast band-sweep measurement method for efficient isotropic sensitivity (EIS) of wireless devices. The method is built on the facts that the relationship between the bit error rate (BER) and the received power is generally consistent in the same band, and the EIS values at a fixed angle is slowly-changing on the frequency except harmonics. Therefore, only few frequency points are required to be measured for a whole band sweep test resulting in a significantly decrease in measurement time.