Abstract: In order to determine the AV90-3 axial compressor’s safe working area in the 0.6m continuous wind tunnel,the test method of reducing the compressor’s inlet volume flow to deter-mine the surge point and that of monitoring the pressure to distinguish the surge are employed. The surge margin of the AV90-3 axial compressor is accurately determined.It comes to the con-clusion that the surge margin is extended to the top-right as the static blade angle increases and the surge margins both above and below atmospheric pressure fit well with that at atmospheric pressure.The surge is prevented occurring effectively by selecting the ratio of the inlet volume flow to the pressure as the anti-surge control parameter,setting alarm and anti-surge curve,and taking by-pass circumfluence.It can provide reference to large-scale continuous wind tunnel com-pressor’s surge margin test and anti-surge control.