A connection device is detachably connected to an object. The object includes a connecting feature. The connection device includes a connecting member, an engaging member and a mounting member. The connecting member includes a base and a connecting portion connected to the base. The engaging member is connected to the connecting member and has an engaging portion. The mounting member is attached to the connecting member. When the mounting member abuts against the connecting feature of the object, the engaging portion of the engaging member is able to be engaged with the object at a position such that the base of the connecting member is connected to the object.