The utility model relates to an indoor evaluation device of emulsion type defoaming agent, including foam installation, foam height detecting device, data record and processing apparatus, characterized by foam installation, constitute by agitator motor, stirring rake and glass beaker, stirring rake upper portion is fixed with agitator motor perpendicular the connection, and the glass beaker bottomis arranged in to the stirring rake lower part, foam height detecting device export by collimated light source that the post is received to post, sensitization intensity and the base is constituteed,on arranging glass beaker in base, the base is arranged perpendicularly in to collimated light source output post with sensitization intensity receipt post on, be located glass beaker's the left andright sides, data record and processing apparatus are the computer and data connecting line constitutes, and wherein data connecting line one end is connected in the computer, and the other end is received the post with sensitization intensity and is linked to each other. Realized the evaluation of stirring system promote lactation liquid type defoaming agent effect, foam altitude variation mainlyrelies on the change of illumination light -transmitting strength to carry out monitoring recording, has guaranteed the accuracy that detects.