A hinge mechanism, wherein the hinge mechanism comprises: a fixation seat having a first containing indentation; a first guiding element mounted in the first containing indentation; a first guided assembly, which is mounted at the first containing indentation of the fixation seat, corresponds to and abuts the first guiding element; a movable assembly comprising a shaft axially movable and pivotable, mounted through the fixation seat and the first containing indentation; and a door-fixing component mounted at the shaft, such that the door-fixing component is pivotable relative to the fixation seat via the shaft; wherein when the shaft is connected to the first guided assembly, the pivoting door-fixing component is moved up and down via the first guided assembly guided by the first guiding element; wherein the hinge mechanism is characterized in that: the fixation seat has a second containing indentation; the first containing indentation and the second containing indentation arranged axially up and down and opposite to each other and in spatial communication with each other; a second guiding element mounted in the second containing indentation; the hinge mechanism comprises a second guided assembly, which is mounted at the second containing indentation of the fixation seat, corresponds to and abuts the second guiding element; the first guided assembly is guided by the first guiding element to move away from the second guided assembly or move back, and the second guided assembly is guided by the second guiding element to move away from the first guided assembly or move back; the shaft is mounted through the second containing indentation and optionally connected to one of the first guided assembly and the second guided assembly; and when the shaft is connected to the second guided assembly, the pivoting door-fixing component is moved up and down via the second guided assembly guided by the second guiding element. a fixation seat having a first containing indentation; a first guiding element mounted in the first containing indentation; a first containing indentation; a first guiding element mounted in the first containing indentation; a first guided assembly, which is mounted at the first containing indentation of the fixation seat, corresponds to and abuts the first guiding element; a movable assembly comprising a shaft axially movable and pivotable, mounted through the fixation seat and the first containing indentation; and a door-fixing component mounted at the shaft, such that the door-fixing component is pivotable relative to the fixation seat via the shaft; a shaft axially movable and pivotable, mounted through the fixation seat and the first containing indentation; and a door-fixing component mounted at the shaft, such that the door-fixing component is pivotable relative to the fixation seat via the shaft; wherein when the shaft is connected to the first guided assembly, the pivoting door-fixing component is moved up and down via the first guided assembly guided by the first guiding element; wherein the hinge mechanism is characterized in that: the fixation seat has a second containing indentation; the first containing indentation and the second containing indentation arranged axially up and down and opposite to each other and in spatial communication with each other; a second guiding element mounted in the second containing indentation; the hinge mechanism comprises a second guided assembly, which is mounted at the second containing indentation of the fixation seat, corresponds to and abuts the second guiding element; the first guided assembly is guided by the first guiding element to move away from the second guided assembly or move back, and the second guided assembly is guided by the second guiding element to move away from the first guided assembly or move back; the shaft is mounted through the second containing indentation and optionally connected to one of the first guided assembly and the second guided assembly; and when the shaft is connected to the second guided assembly, the pivoting door-fixing component is moved up and down via the second guided assembly guided by the second guiding element.