Random fiber lasers (RFLs) have attracted extensive attention due to their rich physical properties and wide applications. Here, a RFL using a cascaded fiber loop mirror (CFLM) is proposed and presented. A CFLM with 10 fiber loop mirrors (FLMs) is simulated by the transfer matrix method and used to provide random feedback. Multiple spikes are observed in both the simulated and measured reflection spectra. The RFL operates in a single longitudinal mode near the threshold and a time-varying multilongitudinal mode at higher pump powers. The RFL exhibits a time-varying radio-frequency spectrum. The Lévy–Gaussian distribution transition is observed, as in many RFLs. The operation mechanism of the lasing longitudinal modes and the impact of complex mode competition and mode hopping on the output characteristics are discussed through experimental and theoretical results. In this study, we unveil an artificial random feedback structure and pave another way for the realization of RFLs, which should be a platform for multidisciplinary studies in complex systems.