The invention relates to a seed planting tool used for a seed transplanter. Based on the seed planting tool used for a present seed transplanter, a main space part in the interior of the seed planting tool is provided with a seed planting toolbox in which lubricating oil is stored, a seed pushing tool is provided with an axis part sliding in a bearing part in the seed planting toolbox, and a seed pushing part tightly fastened with the front end of the axis part outside of the seed planting toolbox, the position lower than the bearing part next to the seed planting toolbox is provided with an oil seal which is contacted with the peripheral surface of the axis part, the lubricating oil gradually intrudes into the clearance owing to the sliding of the axis part, the danger that the lubricating oil received by the oil seal can not flow to anywhere and then can leak to the exterior of the seed planting toolbox through the middle part of the oil seal and the axis part exists, and as the lubricating oil leaks outwards, the danger that farmlands on which seeds are planted can be polluted and the durability of the seed planting tool can be reduced owing to the deficiency of lubricating oil in the seed planting toolbox exists. A solution refers to that a hollow part is arranged between the oil seal and the bearing part, and a communication groove which is communicated from the hollow part to the main space part is also arranged.
