The utility model relates to a large-particle niobium-material super conductive cavity which belongs to the field of nuclear technology and applied accelerators. The super conductive cavity comprises one elliptical cavity body made of niobium material or at least two elliptical cavity bodies made of niobium material in series connection. Both end openings of the cavity body are respectively connected with a beam tube, and the other end of each circular tube is connected with a flange. The utility model is characterized in that a wall board made of niobium material of the elliptical cavity body made of niobium material is provided with a plurality of large particles of which the diameters are in centimeter magnitude orders. The utility model uses the large grain niobium board for replacing the traditional super conductive cavity made of the niobium board of small particle size, and improves the accelerating performance of the super conductive cavity. The improved aspects are that the quality factor Q of the cavity is obviously increased, and the accelerating gradient Eacc is greatly increased. For example, the quality factor of the super conductive cavity of which the frequency is 1.5 GHz is increased from 5*10< 9 > to 1*10< 10 >, and the accelerating gradient reaches 36.6 MV/m which is about 16MV/m higher than the accelerating gradient of the super conductive cavity of small particle size.