Abstract: The standard method of formaldehyde detection of indoor environmental pollution in civil build.ing engineering has been changed from the phenol reagent spectrophotometric method in the original na-tional standard CB 50325-2010 to the AHMT spectrophotometric method in CB 50325-2020, and thejimit of formaldehyde concentration in indoor air has been increased. In view of this change, this papelanalyses the experimental principles, detection limits, analytical procedures, advantages and disadvantages of the two formaldehyde testing methods, and concludes that the AHMT spectrophotometric method ismore suitable for social development and protection of people's health than the phenol reagent method interms of stability and accuracy in the detection of formaldehyde in a mixed environment with indoor envi-ronmental pollutants.

Key words: indoor air, standard of formaldehyde detection, formaldehyde detection, phenol reagentmethod, AHMT spectrophotometric method