Disclosed is a portable carbon dioxide gas-sensing electrode. The portable carbon dioxide gas-sensing electrode is characterized by comprising an electrode shell (1); an electrode film cap (2) is locked at the testing end of the electrode shell (1), a sealing ring (3) is arranged between the electrode film cap (2) and the electrode shell (1), an inner cavity of the electrode shell (1) is filled with electrode filling liquid (4), an internal reference electrode (5) is arranged at the testing end of the electrode shell (1) to seal the inner cavity of the electrode shell (1), the internal reference electrode (5) is located inside the electrode film cap (2), an internal measuring electrode (6) and the internal reference electrode (5) are fixed together, the internal measuring electrode (6) is located at the outer end of the internal reference electrode (5), a gas-permeable film (7) is arranged at the outer end of the electrode film cap (2), and the connecting end of the electrode shell (1) is connected with a connector assembly (9) through a wire (8). The portable carbon dioxide gas-sensing electrode can be used for detecting the total amount of water soluble carbon dioxide, carbonate and bicarbonate.