The DC power filter board adopts the working principle of LC differential common mode, which can suppress the interference in the switching power supply or other DC power supplies, reduce the ripple of the power supply, and reduce the interference caused by the power supply. It can be used in low-voltage DC power supply circuits, such as power amplifiers.Boards, vehicle equipment, industrial control panels, DC appliances, etc.This circuit is more flexible to use. When the suppression effect is not up to the requirement, it can be connected in multiple stages to enhance the suppression ability. When the working current is not up to the requirement, multiple blocks can be connected in parallel to increase the output current. It can be used for circuit boards that use positive and negative power supplies.The two pieces are superimposed to form a positive and negative power interference suppression board.The board is divided into two voltage specifications, 0~25V, 0~50V, and the matching filter board can be selected according to the working voltage range used.