The size of loose circle has an important influence on the determination of roadway support parameters. In order to optimize the support scheme, the study of loose circle test was carried out in Xingdong Mine. On the basis of comparing the current commonly used test methods, in order to improve the accuracy, the method of combining acoustic wave test and borehole peeping was adopted. Seven peep holes and three acoustic test holes were arranged. The results showed that the average failure depth of the roadway roof was 2.0 m, and the average failure depth of the two sides of the roadway was 4.5 m. Based on the analysis of the test results, the roof support parameters of the current scheme were more suitable, and the parameters such as the roadway side anchor cable and the support attachment were optimized. The mine pressure observation showed that the roof subsidence of the roadway was reduced by 12 %, and the both sides convergences were reduced by 33 %.