A capacitance circuit board signal-adjusting device, and more particularly, a signal adjusting device capable of increasing the clarity of a high frequency signal; the signal adjusting device includes a circuit board disposed in a connector, a plurality of transmission circuits disposed on the circuit board, one side of the transmission circuit is a signal input terminal and another side thereof is a signal out terminal; it is characterized in that a copper foil in the middle section of transmission circuit is planned in advance to generate a capacitor naturally by breaking off a slit; the capacitor including two parallel sections arranged distantly side by side, a medium disposed between the two parallel sections and two breaches disposed in two directions opposite to each other at two diagonal ends. Whereby, the capacitor naturally generated in the circuit board plus a resistor connected thereto in parallel can constitute a signal filter; it can reduce components, shorten the manufacturing process, reduce the cost and achieve the good signal adjustment effect while being put into practice.