Abstract: Theoretical analysis on macro stress of Haizi coal mine,the principle and method for measuring initial stresses in rock using acoustic emission effect are described.Through sampling in 9 special directions on the beamed rock cores in Haizi coal mine and doing acoustic emission experiment,the unilateral plus stress values on each direction are obtained.The principle stress value at every measurement point is compressive stress value.It is suggested that the Haizi coal mine is in structural stress field.And then the data are introduced into the crustal stress calculating formula,and then the values,azimuth angle and obliquity of the three principal stresses are obtained.The experiment result is in accordance with actual situation.