A needle device, comprising a needle base and a needle head, the needle base having a first side which is close to skin when using, the needle head having a first end which is connected to the needle base, the needle head extends parallel to the first side, wherein the needle device further comprises: a first structure part, the first structure part is arranged outside the needle base and slip matches with the needle base along extension direction of the needle head, a first limit mechanism is arranged between the first structure part and the needle base, the first limit mechanism is adapted to prevent the first structure part being separated from the needle base along extension direction of the needle head; a second structure part, the second structure part is arranged outside the first structure part and slip matches with the first structure part along extension direction of the needle head, a second limit mechanism is arranged between the first structure part and the second structure part, the second limit mechanism is adapted to prevent the second structure part being separated from the first structure part along extension direction of the needle head; the first structure part and the second structure part are adapted to slide along the extension direction of the needle head for holding a second end opposite to the first end into the second structure part; and the needle base at least comprises an installation portion, the installation portion is a segment of the needle base that may be covered by the first structure part during process of slip match of the first structure part, the first structure part does not exceed first side of the installation portion; the second structure part has a bottom structure which exceeds the first side of the installation portion; inner wall of the bottom structure slip matches with the first side of the installation portion. a first structure part, the first structure part is arranged outside the needle base and slip matches with the needle base along extension direction of the needle head, a first limit mechanism is arranged between the first structure part and the needle base, the first limit mechanism is adapted to prevent the first structure part being separated from the needle base along extension direction of the needle head; a second structure part, the second structure part is arranged outside the first structure part and slip matches with the first structure part along extension direction of the needle head, a second limit mechanism is arranged between the first structure part and the second structure part, the second limit mechanism is adapted to prevent the second structure part being separated from the first structure part along extension direction of the needle head; the first structure part and the second structure part are adapted to slide along the extension direction of the needle head for holding a second end opposite to the first end into the second structure part; and the needle base at least comprises an installation portion, the installation portion is a segment of the needle base that may be covered by the first structure part during process of slip match of the first structure part, the first structure part does not exceed first side of the installation portion; the second structure part has a bottom structure which exceeds the first side of the installation portion; inner wall of the bottom structure slip matches with the first side of the installation portion.