The invention relates to the technical field of crop equipment, and provides a seed image acquiring device and an acquiring method thereof. The device comprises a stent assembly and a shadow removing device capable of removing the shadow of a seed to be measured. The shadow removing device comprises a box body with an opening in one end and a cover body capable of covering the opening, and the seed to be measured is arranged on the cover body. A luminescent part which can illuminate the cover body to remove the shadow of the seed to be measured on the cover body is arranged in the box body. The device further comprises an imager which is arranged on a horizontal support bar of the stent assembly and is capable of acquiring an image formed by the orthographic projection of the seed to be measured on the transparent cover body. According to the device, the resolution of the acquired image the seed to be measured is high, and subsequent surface area measurement of the seed to be measured is accurate.