An air interface simulator and simulation method is disclosed. The air interface simulator comprises a first plurality of variable attenuators for equally providing a mobile station with a transmission signal received from base transceiver station (BTS) before the air interface simulator starts driving, a plurality of attenuators for generating path loss to prevent power of the mobile station from being excessively input to said BTS and to construct an air environment, a first plurality of 2-way dividers for generating an input terminal for providing load in a reverse link of the BTS and combining the provided load and a RF signal of the mobile station, a plurality of duplexers for duplexing a transmission signal and a received signal of the BTS into a RF signal of the mobile station, a second plurality of variable attenuators for generating path loss and long-term effect, a first plurality of 4-way dividers for combing input signals from each BTS, a second plurality of 4-way dividers for combining input signals from each mobile station and a decoder circuit for controlling the first and second plurality of variable attenuators, the decoder circuit being provided with control input from a parallel port of a control computer.