A fixing device (B), comprising a base , and a pressing block mechanism , the base and the pressing block mechanism are disposed in a first direction, the base comprises an inner side wall, the pressing block mechanism comprises two pressing plates , the two pressing plates are respectively connected to a locking rod , the two pressing plates are rotatably connected together to change between an unfolded state and a folded state, a rotation axis of the two pressing plates is disposed in the first direction, outlines of the pressing block mechanism in the unfolded state and the folded state are different, the inner side wall of the base protrudes to define two connecting bases , at least one of the locking rods is configured to move relative to the base between a working state and a movable state, movement of the at least one of the locking rods between the working state and the movable state cooperates with the change of the pressing block mechanism between the unfolded state and the folded state, and the locking rods , when in the working state, cooperate with the two connecting bases to enable a fixed object to be clamped between the two pressing plates and the base to achieve a fixed connection through the locking rods , characterized in that the fixing device further comprises a rotation shaft , wherein the two pressing plates are rotatably connected together by the rotation shaft . a base , and a pressing block mechanism , the base and the pressing block mechanism are disposed in a first direction, the base comprises an inner side wall, the pressing block mechanism comprises two pressing plates , the two pressing plates are respectively connected to a locking rod , the two pressing plates are rotatably connected together to change between an unfolded state and a folded state, a rotation axis of the two pressing plates is disposed in the first direction, outlines of the pressing block mechanism in the unfolded state and the folded state are different, the inner side wall of the base protrudes to define two connecting bases , at least one of the locking rods is configured to move relative to the base between a working state and a movable state, movement of the at least one of the locking rods between the working state and the movable state cooperates with the change of the pressing block mechanism between the unfolded state and the folded state, and the locking rods , when in the working state, cooperate with the two connecting bases to enable a fixed object to be clamped between the two pressing plates and the base to achieve a fixed connection through the locking rods , characterized in that the fixing device further comprises a rotation shaft , wherein the two pressing plates are rotatably connected together by the rotation shaft . the two pressing plates are respectively connected to a locking rod , the two pressing plates are rotatably connected together to change between an unfolded state and a folded state, a rotation axis of the two pressing plates is disposed in the first direction, outlines of the pressing block mechanism in the unfolded state and the folded state are different, the inner side wall of the base protrudes to define two connecting bases , at least one of the locking rods is configured to move relative to the base between a working state and a movable state, movement of the at least one of the locking rods between the working state and the movable state cooperates with the change of the pressing block mechanism between the unfolded state and the folded state, and the locking rods , when in the working state, cooperate with the two connecting bases to enable a fixed object to be clamped between the two pressing plates and the base to achieve a fixed connection through the locking rods , characterized in that the fixing device further comprises a rotation shaft , wherein the two pressing plates are rotatably connected together by the rotation shaft . <EOS>