An exemplary optical module testing apparatus (100) includes a base (10) and a supporting element (20). The base has a testing hole (13) formed thereon. The supporting element has a plurality of supporting portions (23) formed thereon. The supporting element is slideably disposed on the base in such a manner that the supporting portions can be selectively aligned with the testing hole. The supporting portions are configured for supporting optical modules. The base has an upper surface (11), and a slide groove (12) is formed on the upper surface, and two slide slots (121) are formed on two sides of the slide groove.