A real-time model for two-headed mirrored disks with autonomous heads is proposed in this paper. Two-headed disks (THD) in this system have two independent arms which can seek cylinder autonomously. Three real-time disk-scheduling algorithms are presented for such disk systems. According to simulation experiments, the algorithm which is called ignore missed deadlines (IGM-EDF) has the best performance, because IGM-EDF does not process those real-time requests which have missed deadlines. The comparison between two-headed mirrored disk with fixed heads(FTMD) and the disk system with autonomous heads (ATMD) is also analyzed in this paper. Because two heads in THD can seek cylinder independently, the performance of ATMD is better than that of FTMD.