Water hardness on-line analyzer

The utility model discloses a water hardness on-line analyzer which comprises a cabinet body, a controller, a touch screen, a universal serial bus (USB) interface, a cabinet door, a mounting box, a supporting plate, a supporting strip, a first supporting frame, a second supporting frame, a liquid storage tank, a test tube, a plug, a glass tube and a detection part, a vertical touch screen is fixed to the middle of the front end of the controller, a horizontal USB interface is fixed to the left portion of the front end of the controller, and a vertical cabinet door is hinged to the front end of the bottom of the cabinet body. Through the arrangement of the controller, the multi-position valve and the optical analysis sensor, not only can the automatic hardness analysis be realized, but also a plurality of water samples can be continuously analyzed, so that the trouble of frequently replacing the water samples is avoided; and the glass tube which can be inserted into the bottom of the test tube can avoid the pr