The invention relates to a multi-turn encoder adopting reed pipes and a direction judging and turn-number counting method thereof and belongs to a multi-turn encoder and a direction judging and turn-number counting method thereof. A rotation turn number counting function of the encoder is achieved by adopting one, two or three reed pipes, the detection of the reed pipes changes with a magnetic field rotating about an axis of the encoder, and opening and closing states are switched to turn on or turn off a follow-up counting circuit so as to calculate the rotating turn number of the encoder. For avoiding counting data loss under the outage condition of a main power supply circuit, a battery is additionally added to keep the counting function under the outage condition. For prolonging the service life of the reed pipes, it is ensured that no switching action is executed under the energization condition, a coil can be wound on the outside, the problem of existing structural complex at present is solved by controlling the switching functions of the reed pipes through the controller, good stability properties are ensured, and the reliability is high.