The invention discloses a steel wire rope length measurement and blanking device and a steel wire rope length measurement and blanking method. The steel wire rope length measurement and blanking device comprises a support, a measurement assembly, a cutting mechanism and a rolling mechanism, wherein the measurement assembly, the cutting mechanism and the rolling mechanism are arranged on the support. In the steel wire rope length measurement and blanking process, after measurement and length recording are conducted through an electronic meter gauge, a steel wire rope is wound on a roller and isin the tensioned state; when the length, measured through the electronic meter gauge, of the steel wire rope reaches the set length, the steel wire rope is cut off through the cutting mechanism, andat the moment, the length of the steel wire rope wound on the roller is the set length; then, the roller is driven by a piston rod of a first piston cylinder to move downwards, the steel wire rope wound on the roller is separated from the roller, an at the moment, measurement and blanking of the steel wire rope are completed. After being unwound, the steel wire rope is wound on the roller; the roller is driven by a motor to rotate for secondary rolling, and the steel wire rope is easy to straighten; and the length of the steel wire rope is measured through the electronic meter gauge, the length control precision of the steel wire rope is high, and the error of every 100 meters does not exceed one centimeter.