Secure deletion plays a crucial role in safeguarding privacy and maintaining confidentiality. Historically, secure deletion was achieved on magnetic storage devices by data overwriting. However, with the rapid advancements in magnetic storage technology, existing secure deletion strategies are still oblivious to the unique characteristics of these storage devices. As a result, there is currently a lack of research effectively addressing the implementation of secure deletion for the emerging interlaced magnetic recording (IMR) technology. Regrettably, applying traditional read-modify-write (RMW) processes to enable secure deletion on IMR technology leads to significant challenges such as severe write amplification (WA) and performance degradation. In this paper, we propose move-on-cover (MOC), a novel secure deletion strategy for securely deleting on IMR, to optimize the performance of secure deletion. Specifically, when securely deleting a bottom track, the MOC first moves one of affected top track to a free top track, and then covers the to-be-deleted bottom track with another top track, minimizing redundant data backups and hiding secure deletion latency of bottom tracks. A series of evaluation experiments show that MOC is highly effective in reducing extra I/Os and improving the performance of secure deletion.