The invention belongs to the technical field of ambulances, and in particular relates to a plug-in mechanism for changing ambulances, comprising: a snap-in claw, a lifting cylinder and a wedge, and a claw that can be inserted into the annular snap-in groove is arranged on the inside of the snap-in claw , the outer side of the snap-in claw is slid on the inner wall of the lifting tube along the circumferential direction, and a wedge is set on the sliding path of the snap-in claw, and the plugging mechanism is provided with a lifting tube, which can be hidden in the rescue compartment, so that the rescue compartment can Plug in from left, right, top and rear. The snap-in claws used for fixing are connected with snap-in claw links. The snap-in claw links are connected to the lifting cylinder and the fixed cylinder through chute. The clamping claw connecting rod lowers the lifting tube, and after the lifting tube is lowered to the loading plane, continue to rotate the clamping claw connecting rod, and the clamping claw is embedded in the annular slot on the side of the fixed column to achieve fixation. The fixing process only needs to rotate the clamping claw to connect The rod can realize two actions of dropping and snapping.