Abstract: In order to strengthen the understanding of the phenomenon of “gyrostat” appearing in the draw body under a flexible isolation layer， based on the concept of traditional ore drawing with the facade and a large number of numerical test models of synchronous ore drawing filling and retention method， a numerical experiment was carried out to study the reproduction law of nonsynchronous ore drawing gyrostat under the flexible isolation layer by using the data processing and picture output function in PFC. The results showed that under different combination schemes， the overall shape of isolation layer is W-shaped. In the priority order of ore drawing， the impact of the ore drawing priority on the isolation layer is different. Under different working conditions， the cavity appearing in the isolation layer shows macroscopic characteristics in the late stage of ore drawing. The transverse frictional effect of isolation layer during ore drawing promotes the transformation of draw body from ellipsoid to gyrostat. The conversion degree of gyrostat depends on whether the ore drawing control is uniform or not.

Key words: mining engineering, flexible isolation layer, non-synchronous ore drawing, gyrostat, numerical test