Abstract: High-density 3D seismic prospecting which has high accuracy for the detection of small faults and concealed geological bodies provides reliable geological guarantees for safe and efficient mining of coalfield. In order to apply the high density 3D seismic exploration technique to coal geological exploration, the design method of 3D seismic geometry in coal field is studied from the angle of affecting the quality of original seismic data. Based on the practice in Huaibei Mining Area, the basic principles for selecting the main parameters of the high-density 3D seismic exploration geometry, such as the fold numbers, bin size, offset, stationline distance and source row distance, are demonstrated in detail. As a result, the geometry for exploration targets was established. Through the method of bin statistics analysis, the effects of fold numbers, offset and azimuth on the quality of seismic data are analyzed, which provides a basis and reference for the geometry design of high-density 3D seismic prospecting in coalfield.