Earth-up weeding device and method and sweet potato planting method

The invention discloses an earth-up weeding device. The device comprises a middle coulter, a left coulter, a right coulter, a pull handle, a coulter fixing mechanism and a pull handle fixing mechanism. The middle coulter is fixed to the front end of the coulter fixing mechanism, the left coulter and the right coulter are installed at two sides of the coulter fixing mechanism and arranged through asplay mode, the pull handle fixing mechanism is installed on the middle coulter or the coulter fixing mechanism, and the pull handle is fixed through the pull handle fixing mechanism. According to the earth-up weeding device, weeding and earth-up are conducted through the middle coulter, the left coulter and the right coulter, the device moves forwards along a ditch just by pulling the pull handle, and planting and ditching of dry crops can be conducted; weeding can also be conducted through the mode, soil is cultured and covers a ridge, the aim of covering the crops for intertillage is achieved, and the earth-up wee