The invention relates to a method for weakening the cardinal plane texture of a magnesium alloy plate strip, which comprises the following steps of: placing the magnesium alloy plate strip between corrugated rollers, carrying out alternative rolling for many times under the temperature of 300-550 DEG C, straightening, and water quenching, or carrying out multi-channel one-way or alternative rolling for many times under the temperature of 150-300 DEG C, straightening, carrying out static recrystallization, and annealing; carrying out corrugated rolling at the temperature of over 300 DEG C, andincreasing along with the channel, wherein each flat surface which is vertical to normal direction of the plate strip is respectively applied with shearing force in different directions; inducing dynamic recrystallization, so that the orientation distribution of grains in the plate strip is randomized, and the strength of the cardinal plane texture is reduced; and carrying out corrugated rolling under the temperature of below 300 DEG C, wherein at the position in the plate strip, especially, the position where the repeated wave bending deformation is the most serious, a large amount of twin crystals are produced to enable the grain orientation to deflect, and further, the initial texture is weakened. The invention has the advantages that the process design is reasonable, the equipment is easy to manufacture, the operation process is easy to realize, the defects of the normal plastic deformation and difficulty in weakening of the texture in annealing of the magnesium alloy are overcome, and the efficiency is high. The method is suitable for the large scale of industrial production.