The invention relates to the technical field of integrated circuit manufacture and especially relates to a low additional phase shift digital attenuator including a pai type attenuator composed of a switch tube M1, a switch tube M2, a resistor Rs and a resistor Rp; a microstrip line, a low-pass network, a resistor Rc and a capacitor Cc. The low-pass network is connected with the switch tube M1 in parallel. The input terminal and the output terminal of the low-pass network are connected with the resistor Rc in series. The capacitor Cc is connected with the resistor Rs. The microstrip line is connected to two ends of the resistor Rs in series. The low additional phase shift digital attenuator provided by the invention is simple in structure, easy to implement and low in chip area occupancy. Additional phase shift of the attenuator can be reduced effectively and requirements for extreme low additional phase shift can be met.