Abstract: In the calculation of the settlement caused by exploiting the oil and gas, the previous calculation dosen't consider the effect of biot coefficient on the amount of compression and settlement, and defaults the biot coefficient is equal to 1. So the error that the theoretical calculation value deviate from the actual value increases. This may have some impact on the cost of the project investment and project design, in order to study the effect of the settlement amount of Biot coefficient and calculated true formation Settlement. The thesis uses two kinds of methods to obtain biot coefficient of granite samples, which one is acoustic test, another is three axial compression test. Biot coefficient measured by Acoustic test is 0.528. But biot coefficient calculated by that obtained by three axis test method through the drainage test and limit pressure and water pressure equal growth test is 0.665. And in all through establishing the FLAC3D model of land subsidence, Experimental research on effect of Biot coefficient on settlement formation, and writer finds the larger biot coefficient is, the larger ground settlement is .