A catheter apparatus includes a replaceable module, a main body portion and a sensing module. The main body portion includes a tube, a urine guide opening and an elastic unit. The replaceable module includes a control unit. A first terminal of the tube is coupled to the replaceable module and a second terminal of the tube is inserted into the bladder. The urine guide opening is disposed at the second terminal of the tube and used to guide urine into the tube when the second terminal of the tube is inserted into the bladder. The elastic unit is disposed at the second terminal of the tube and coupled to the control unit. The sensing module is coupled to the control unit and used to sense whether the second terminal of the tube is inserted to the correct position in the bladder and transmit sensing result to the control unit.一種導尿管裝置,包含可置換模組、主體部及感測模組。主體部包含導管、尿液引導開口及彈性單元。可置換模組包含控制單元。導管之第一端耦接至可置換模組且導管之第二端插入至膀胱內。尿液引導開口設置於導管之第二端,用以在導管之第二端插入至膀胱內時引導尿液流入導管內。彈性單元設置於導管之第二端並耦接至控制單元。感測模組耦接至控制單元,用以感測導管之第二端是否已插入至膀胱內之正確位置並將感測結果傳送至控制單元。