The invention discloses a high-speed pot seedling Z-shaped wide-narrow row transplanting mechanism. The rice Z-shaped wide-narrow row planting is a high luminous efficient rice agricultural mode, and mainly relies on artificial realization. Two transplanting arms at one side are installed at the left and the right sides of a gear box, and can simultaneously transplant two rows of seedlings. The mechanism combines a variable transmission characteristic of a non circular gear with a space transmission characteristic of a staggered helical gear through the form of a variable differential velocity combination gear system. The wide-narrow row transplanting of the rice pot seedling is realized by a large buckle space ''8-shaped'' track. The two transplanting arms work alternately, and the Z-shaped transplanting is realized. The variable differential velocity combination gear system realizes free transmission ratio through the combination form of a chain wheel and the gear transmission, and the mechanism can realize complex transplanting tracks.