Abstract: An adapter connector includes an insertion terminal, a connecting member, a plurality of connecting tubes, and a plurality of optical fiber cables. Thus, by connection of the quick connector and the insertion posts of the connecting member, each of the optical fiber cables is connected to the testing instrument stably and efficiently, thereby facilitating the testing instrument performing the testing procedures. In addition, each of the optical fiber cables can be removed from the respective connecting tube easily and rapidly, thereby shortening the testing time, and thereby enhancing the testing efficiency.