A biaxial synchronization dual-shaft hinge includes a transmission device set consisting of a first transmission member, a second transmission member, a first interlocking member and a second interlocking member, and pivot shaft set consisting of a first pivot shaft and a second pivot shaft. The arrangement of the transmission device set enables the first pivot shaft and second pivot shaft of the pivot shaft set to be biased synchronously in reversed directions so that the top cover member and bottom base member of the dual-leaf mobile electronic device that are respectively affixed to the first pivot shaft and second pivot shaft of the pivot shaft set can be opened and closed smoothly and stably.