Formaldehyde detection device and method

The invention provides a formaldehyde detection device and method. The formaldehyde detection method comprises the steps of: (A1) introducing gas into an absorption module, and absorbing formaldehydein the gas by an absorbent; (A2) conveying liquid containing formaldehyde in the absorption module to a first gas-liquid separation module by utilizing a first pump; (A3) conveying the liquid subjected to gas-liquid separation in the first gas-liquid separation module to a reaction module by using a second pump, and reacting the liquid containing formaldehyde with a reagent; wherein the relationship between a working phase of the second pump and a working phase of the first pump is that k belongs to z; (A3) conveying the reaction liquid in the reaction module to a second gas-liquid separationmodule; and (A4) conveying the liquid subjected to gas-liquid separation in the second gas-liquid separation module to a detection pool by using a third pump. The method has the advantages of low detection limit, no need of da