A tellurium dioxide (TeO₂) non-collinear acousto-optic tunable filte r (AOTF) is a new kind of light splitting device based on abnormal acousto-optic interaction.Spectral resolutio n is one of the key parameters in the design and applications of an AOTF. In this paper,using the AOTFs designed considering the rotatory property o f the TeO_2crystal,we experimentally investigate the double-filtering perform ance of the two AOTFs arranged in tandem.Adjusting the frequency of the radio frequency source,we can control and enhance the spectral resolution of the filtering system. In the experiment,a 25% enhancement of the spectral resolution has been acquired .Also,it is demonstrated that the double-filtering technique can suppress the sidelobe of the diffracted light be am.So the double-filtering technique is a good method in enhancing the filtering performance of an AOTF.And this tec hnique will promote the applications of an AOTF in hyperspectral imaging and oth er related fields.