The invention discloses a brake opening speed adjusting contactor which comprises a closed shell, an opening and closing mechanism, a rotating rod, a brake opening spring, a contact head spring, an insulating piece and a brake closing electromagnet, wherein the opening and closing mechanism, the rotating rod, the brake opening spring, the contact head spring, the insulating piece and the brake closing electromagnet are positioned in the closed shell; a bottom part of the opening and closing mechanism is connected with the contact head spring, a bottom part of the contact head spring is connected with the insulating piece, one end of the insulating piece is connected with the rotating rod, the brake closing electromagnet is arranged between the rotating rod and an inner wall of the closed shell, the brake closing electromagnet comprises a plurality of adjacently arranged electromagnet wire coils and a plurality of iron cores, the plurality of the electromagnet wire coils are mounted on the inner wall of the closed shell, a switch is mounted on each of electromagnet wire coil, the plurality of iron cores are mounted on the rotating rods and are opposite to corresponding electromagnet wire coils, the brake opening spring is connected between the rotating rod and the inner wall of the closed shell, and the closed shell is filled with inert gases. Via the above structure, the brake closing electromagnet in the brake opening speed adjusting contactor can be used for changing magnitude of magnetic force by adjusting the quantity of connected electromagnet wire coils, opening and closing speed of the brake closing electromagnet can be therefore changed, and cut-off overvoltage protection over the contactor can be realized because the closed shell is filled with the inert gases.