Briquette specimens made of outburst coal are taken as research objects, and both mechanical properties evolution under cyclic loading and law of hysteretic curve evolution under different loading level are studied. The results show that hysteretic loop is composed of load-unload curve when briquette specimens are studied under cyclic loading, and secondary hysteretic loop is produced from the second cycle. The area composed by hysteretic curve becomes smaller with the addition of cycle numbers. The relation between deformation response and loading level is very close. Load-unload curve of hysteretic curve is expressed by conic, and the change law of fitting parameters of conic is very regular with the addition of cycle numbers, but the regularity of the law with loading level isn’t very obvious; the minis sign of fitting parameters of conic is opposite.