The invention discloses a seedling pre-cutting open transverse sugarcane transplanter. The seedling pre-cutting open transverse sugarcane transplanter comprises: a frame; a sugarcane collecting box mounted at the front part of the frame; a first conveying chain mounted at the upper part of the frame and positioned behind the sugarcane collecting box, wherein the front part of the first conveying chain is positioned in the sugarcane collecting box and upwards tilts from head to tail, the rear part of the first conveying chain is horizontally distributed, and the first conveying chain is equidistantly provided with a plurality of seedling taking groves; a sugarcane moving device mounted at the top of the sugarcane collecting box and being able to move the superfluous sugarcane seedlings in the seedling taking grooves of the first conveying chain; and a second conveying chain mounted at the lower part of the frame, positioned below the first conveying chain, upwards tilting from head to tail and equidistantly provided with a plurality of seedling taking grooves. The sugarcane transplanter has the advantages of realization of transverse seedling transplantation, uniformity in seedlingdischarging, reduction of excessive transplantation and missing transplantation of the sugarcane seedlings, and ensuring of accurate plantation.