A spider hinge for a frameless glass door includes a base plate, a pivot block connected to the base plate, a swing base pivotally connected to the pivot block, and a positioning mechanism disposed between the pivot block and the swing base. The swing base has two legs slantwise extending therefrom. Each leg has a round frustum extending therefrom. The round frustum has a threaded hole define in one side thereof for assembling with a fastener. The glass door is secured by fastening the fastener and the round frustum. The positioning mechanism includes two springs and a positioning block connected to the two springs and biased by the springs. The pivot block has multiple cavities for selectively receiving the positioning block to achieve the purpose of positioning the swing base.