The invention discloses a wide-narrow row spacing transplanting mechanism with a two-degree-of-freedom gear train for a pot seedling of paddy rice. The problems that a transverse offset is too big during seedling taking so that insufficient accuracy of the seedling taking is caused exist in an existing wide-narrow row spacing transplanting mechanism with a single-degree-of-freedom planetary gear train for the pot seedling. In the wide-narrow row spacing transplanting mechanism with the two-degree-of-freedom gear train for the pot seedling of the paddy rice, a form of combining gear transmission with chain transmission is adopted in a transmission case of the two-degree-of-freedom gear train; the gear combination of non-circular gears and staggered helical gears is adopted in a gear box; because of two power inputs of the two-degree-of-freedom gear train, the mechanism is enabled to be capable of realizing a transmission ratio which is changed freely by combining the variable-speed transmission characteristics of the non-circular gears; thus, a complicated transplantation trajectory is realized; the trajectory is one straight line during the seedling taking; the transverse offset does not exist; the accurate seedling taking can be realized; the success rate of the seedling taking is guaranteed. A spatial deviation of the wide-narrow row spacing transplanting mechanism with the two-degree-of-freedom gear train for the pot seedling of the paddy rice is mainly realized by the helical gears which are mounted in a staggering manner; the wide-narrow row spacing transplanting mechanism with the two-degree-of-freedom gear train for the pot seedling of the paddy rice is simpler than a spatial bevel gear of an existing mechanism; meanwhile, direct seedling taking is realized in the condition that the wide-narrow row spacing transplantation is guaranteed.