The present invention relates to a machine for slicing stems of sea mustard, comprising: a frame； a first conveying part provided in the frame to convey the stems of sea mustard input in a first direction； a first slicing rotational shaft installed in parallel with the first direction of the first conveying part； a first slicing part having a slicing blade formed in a direction perpendicular to the first slicing rotational shaft to slice the stems of sea mustard conveyed by the first conveying part； a second conveying part receiving the stems of sea mustard conveyed through the first conveying part and conveying the stems of sea mustard in a second direction in parallel with the first direction； a second slicing rotational shaft installed in a direction in parallel with the second direction of the second conveying part； a second slicing part having a slicing blade formed in a direction perpendicular to the second slicing rotational blade to slice unsliced portions of the stems of sea mustard； and a control unit controlling the first slicing part, the second slicing part, and driving of the first and second conveying parts. The first conveying part includes a first tack circulating unit performing continuous track motion in a first chain, a second track circulating unit performing the continuous track motion in a second chain below the first chain； and a third track circulating unit performing the continuous track motion in a third chain below the first chain, wherein the second and third chains are arranged symmetrically on both sides of the first chain at the center to convey the stems of sea mustard introduced between the first chain and the second and third chains. According to the present invention, the machine for slicing the stems of sea mustard can smoothly convey and slice the stems of sea mustard without being influenced by sea mustard input condition change, and is able to maintain uniformity in slicing by synchronizing the sea mustard stem convey parts wi
