Seawater total phosphorus and total nitrogen on-line developing interaction system and control method

The invention relates to the technical field of marine environment monitoring, in particular to a seawater total phosphorus and total nitrogen online developing interaction system and a control method. A first branch of the digestion device is sequentially connected with an electronic condenser, an inlet of a peristaltic pump, an outlet of the peristaltic pump, a copper-plated cadmium column, a chromogenic reaction pipeline, a luminosity measurement pipeline and a reaction reagent bottle; a second branch of the digestion device is sequentially connected with an electronic condenser, an inlet of a peristaltic pump, an outlet of the peristaltic pump, a chromogenic reaction pipeline, a luminosity measurement pipeline and a waste liquid collection bottle. When the handheld interaction instrument is used, a color developing agent concentration control button and a reducing agent concentration control button of the handheld interaction instrument are clicked, and the feeding amount of a reaction reagent is up-regul