A physiological signal detecting device includes a carrier, an electrode layer fixed on the carrier for receiving a physiological signal, and a signal transmitter buckled on the electrode layer and the carrier. The signal transmitter includes a transmitting member and an external connector. The transmitting member includes a first sheet, a column extending from the first sheet, and a thorn curvedly extending from the first sheet. The external connector includes a ring-shaped second sheet and a hollow protrusion extending from an inner edge of the second sheet. The thorn has a sharp end piercing into the electrode layer, the column passes through the electrode layer and the carrier, and a free end portion of the column exposes from the carrier. The protrusion is sleeved at and fastened to the free end portion so that the carrier and the electrode layer are sandwiched between the first and second sheets.
