A capacitive-deionization-type nutritive salt removal system, suitable for use in removing nutritive salts from a dam or a weir containing water having a water bloom therein, the system comprising: an intake pump, configured such that the water is taken in; a first nutritive salt filtration unit, configured such that nutritive salts are primarily filtered from the taken-in water in a capacitive deionization manner, wherein the first nutritive salt filtration unit comprises: a first filter train for primary capacitive deionization, configured such that nutritive salts are primarily filtered from the taken-in water in a capacitive deionization manner, and a second filter train for primary capacitive deionization, configured such that nutritive salts are primarily filtered from the taken-in water in a capacitive deionization manner; a second nutritive salt filtration unit, configured such that nutritive salts are secondarily filtered in a capacitive deionization manner from nutritive salt concentrated water primarily separated through the first nutritive salt filtration unit, wherein the second nutritive salt filtration unit comprises: a first filter train for secondary capacitive deionization, configured such that nutritive salts are secondarily filtered in a capacitive deionization manner from nutritive salt concentrated water primarily filtered through the first filter train for primary capacitive deionization, and a second filter train for secondary capacitive deionization, configured such that nutritive salts are secondarily filtered in a capacitive deionization manner from nutritive salt concentrated water primarily filtered through the second filter train for primary capacitive deionization; and a filtration-direction-switching unit, configured such that a filtration direction is switched so that the primarily filtered nutritive salt concentrated water is transferred from the first filter train for primary capacitive deionization to the first filter train for secondary capacitive deionization or to the second filter train for secondary capacitive deionization depending on control of switching thereof, or so that the primarily filtered nutritive salt concentrated water is transferred from the second filter train for primary capacitive deionization to the first filter train for secondary capacitive deionization or to the second filter train for secondary capacitive deionization depending on control of switching thereof. an intake pump, configured such that the water is taken in; a first nutritive salt filtration unit, configured such that nutritive salts are primarily filtered from the taken-in water in a capacitive deionization manner, wherein the first nutritive salt filtration unit comprises: a first filter train for primary capacitive deionization, configured such that nutritive salts are primarily filtered from the taken-in water in a capacitive deionization manner, and a second filter train for primary capacitive deionization, configured such that nutritive salts are primarily filtered from the taken-in water in a capacitive deionization manner; a second nutritive salt filtration unit, configured such that nutritive salts are secondarily filtered in a capacitive deionization manner from nutritive salt concentrated water primarily separated through the first nutritive salt filtration unit, wherein the second nutritive salt filtration unit comprises: a first filter train for secondary capacitive deionization, configured such that nutritive salts are secondarily filtered in a capacitive deionization manner from nutritive salt concentrated water primarily filtered through the first filter train for primary capacitive deionization, and a second filter train for secondary capacitive deionization, configured such that nutritive salts are secondarily filtered in a capacitive deionization manner from nutritive salt concentrated water primarily filtered through the second filter train for primary capacitive deionization; and a filtration-direction-switching unit, configured such that a filtration direction is switched so that the primarily filtered nutritive salt concentrated water is transferred from the first filter train for primary capacitive deionization to the first filter train for secondary capacitive deionization or to the second filter train for secondary capacitive deionization depending on control of switching thereof, or so that the primarily filtered nutritive salt concentrated water is transferred from the second filter train for primary capacitive deionization to the first filter train for secondary capacitive deionization or to the second filter train for secondary capacitive deionization depending on control of switching thereof.