The invention discloses a high-voltage DC relay movable contact spring deflection prevention mechanism, which comprises a movable contact spring. the movable contact spring is linked with a push rod; the upper section of the push rod is located above a yoke and is fixed with the movable contact spring; the yoke is provided with a positioning plate; reaction springs are connected between the left part of the movable contact spring and the positioning plate, and between the right part of the movable contact spring and the positioning plate; at least one of the hook at the upper end and the hook at the lower end of the reaction spring is fixed with a sliding rod; the hook can slide on the sliding rod; the sliding rod comprises an upper sliding rod fixed with the upper hook of the reaction spring and the lower sliding rod fixed with the lower hook of the reaction spring; the upper sliding rod is fixed with the movable contact spring; and the lower sliding rod is fixed with the positioning plate. The high-voltage DC relay movable contact spring deflection prevention mechanism has the advantages that the phenomenon that the movable contact spring deflects and thus a moving contact and a static contact can not be broken rapidly due to assembly can be avoided, and vertical movement of the push rod to drive the movable contact spring to deflect can be prevented.