The invention discloses a laser multi-pass amplifier based on tandem connection of two discs. The laser multi-pass amplifier based on tandem connection of the two discs comprises a first parabolic reflector, a second parabolic reflector, a third parabolic reflector, a fourth parabolic reflector, a first disc laser crystal and a second disk laser crystal, wherein the first parabolic reflector, the second parabolic reflector, the third parabolic reflector and the fourth parabolic reflector are arranged coaxially in sequence, the first parabolic reflector and the second parabolic reflector are arranged in a conjugated mode, and the third parabolic reflector and the fourth parabolic reflector are arranged in a conjugated mode; the surface of the first parabolic reflector is provided with a pumping light incident hole and a seed laser incident hole, and the center of the first parabolic reflector is hollowed out for containing the first disc laser crystal; the center of the fourth parabolic reflector is hollowed out for containing the second disc laser crystal; the center of the second parabolic reflector and the center of the third parabolic reflector are hollowed out. Through the laser multi-pass amplifier based on tandem connection of the two discs, the optical length of the disc laser crystals can be extended, the spontaneous radiation effect of laser is restrained, the power of output laser is increased, and the equivalent thickness of the disc laser crystals is increased; consequently, the pumping frequency of the disc laser crystals is increased, the absorption efficiency of the pumping light is improved, and the power of the output laser is further improved.