According to the loose stratum, easy collapsing, block-falling and hole diameter shrinkage in the tertiary coalfield exploration for Baoshan-Zhenxin coalfield, application of general double-tube and wireline coring drilling have their own advantages and disadvantages. But by enlarging SA75 wire-line coring drilling tool and hole reamer to 80mm in diameter with corresponding measures of drilling and coring, high quality, high efficiency and preferable benefit were achieved.