The disclosure relates to a biaxial hinge mechanism including a positioning plate, a first main shaft, a second main shaft, a cam, and a linkage assembly. The positioning plate has a first through hole and a second through hole. The first main shaft is movably disposed through the first through hole. The second main shaft is rotatably disposed through the second through hole. The cam is fixed on the second main shaft. The linkage assembly is connected to the first main shaft and movable with the cam. When the second main shaft is rotated in a specific direction, the cam pushes the linkage assembly to force the first main shaft to move away from the second through hole so as to increase an axis distance between the first main shaft and the second main shaft. In addition, the disclosure relates to an electronic device having the biaxial hinge mechanism.