Abstract: The present invention relates to an assembled, downward-pressing, multifunctional electroencephalogram (EEG) cap, at least comprising: a cap body, configured to be worn on a head of a patient, and formed by a plurality of constituent blocks, wherein each of the constituent blocks comprises a first unit and a second unit that carry extracranial electrodes for detecting EEG signals from corresponding areas of the head of the patient, in which the first unit and the second unit are configured to perform relative movements and thereby change their relative positions, the first unit and the second unit being shaped to fit a curved surface of the head of the patient; the first unit of the constituent block being movably connected to the second unit by means of a drive system provided between at least a part of the first unit and a part of the second unit, wherein the extracranial electrodes located on the first unit and on the second unit are configured to at least follow the relative movements between the first un