The invention relates to the field of pasture harvesting machinery, in particular to an automatic harvesting and scattering device for pasture. The device comprises a frame, the front end of which is provided with a harvesting device. The harvesting device comprises a rotary shaft fixedly connected with the front end of a frame through a connecting rack. Two ends of the rotary shaft are movably clamped into rotary holes in the front ends of the connecting rack. One end of the rotary shaft is fixedly connected with a harvesting driven wheel. The connecting end surface on the same side with the harvesting driven wheel is provided with a harvesting motor. An output shaft of the harvesting motor is provided with a harvesting driving wheel. The rotary shaft of the connecting rack is movably provided with a rotary material cutting part. Two sides at the front end of a frame are provided with conveying devices. The automatic harvesting and scattering device for pasture has the following beneficial effects: the device is simple in structure, reasonable in design and simple in operation; pasture is rapidly cut when being harvested; after cutting, pasture can be quickly collected and dried; the people's demands are effectively met; and problems in the prior art are solved.