The utility model belongs to installation, repair tools, concretely relates to rotary blowout preventer dismantles installation special spanner, rotary blowout preventer dismantles installation special spanner include body, fixture block, afterburning pole penetrate the hole, the card post, the body be the tourus, a plurality of draw -in grooves are offered to the terminal surface equipartition of body, the fixture block is connected to the draw -in groove, the radial equipartition of body is offered a plurality of afterburning poles and is penetrated the hole, a plurality of calories of post holes are offered to body axial equipartition, card post jogged joint card post, this rotary blowout preventer dismantles installation special spanner convenient operation, nimble changeable, narrow and small space has been solved simultaneously in its lighting of maximum messenger, difficult technical problem breaks out on the dark annular space space.