The invention discloses a salt depletion alertor and a soft water processor containing the alertor. The salt depletion alertor comprises a protective shell, an eccentric simple pendulum, a reed pipe plug and a magnet, and the eccentric simple pendulum is rotatably connected with the protective shell; the reed pipe plug is fixedly arranged on the protective shell; the eccentric simple pendulum is of an asymmetric structure and is provided with a rotation shaft, and the magnet is embedded in the far end of the rotation shaft; a positioning hole is correspondingly formed in the protective shell and used for containing the rotation shaft; the eccentric simple pendulum rotates between a contact position and a natural position. The soft water processor comprises the salt depletion alertor and asalt box with a salt well arranged inside. The salt depletion alertor is simple in design and structure, practical, high in interference resisting capacity, convenient to maintain and clean, low in failure rate, lower in cost and wider in application range; in addition, multiple sets of salt depletion alertors can be mounted at different heights, and the functions such as pre-alarm of all proportions or displaying of surplus salt amount can be achieved by extracting multiple salt level signals in the salt box.