Recently, halide perovskites (HPs), which exhibit resistive switching (RS) behaviors, are proposed as a promising candidate for next‐generation memory because of their low power consumption, low cost, and mechanical flexibility. However, HP‐based memories have crucial problems related to short endurance and vague switching mechanism. Here, the RS behaviors of switchable methylammonium lead iodide (MAPbI₃) and nonswitchable rubidium lead iodide (RbPbI₃) mixtures are reported and it is elucidated on the source of the switching phenomena. By controlling the ratio of rubidium iodide (RbI)/methylammonium iodide (MAI), five compositions of the mixture of RbPbI₃ and MAPbI₃ (Rb_1−xMA_xPbI₃, x = 0, 0.31, 0.52, 0.71, and 1) films are fabricated. The mixtures of cubic MAPbI₃ and orthorhombic RbPbI₃ films exhibit excellent performances in Ag/polymethyl methacrylate/Rb_1−xMA_xPbI₃/Pt cells, with endurance of 10³ cycles, a high on/off ratio of 10⁶, and an operation speed of 640 µs. Plausible explanations for the switching mechanism are provided based on Ag bridges by using the combination of conductive atomic force microscopy and energy dispersive X‐ray spectroscopy. It is suggested nonswitchable RbPbI₃ contributes to the endurance enhancement by restraining the growth of Ag bridges. The unique approaches provide a new strategy to overcome the bottleneck of the HP‐based RS memories for next‐generation computing.