Perovskite memristors’ switching mechanism mainly consists of filaments formation and rupture. It is challenging to investigate filaments because their formation and rupture are random events in nano scale that exactly cause memristor, set, and reset voltage instability. Consequently, filament formation and rupture can be controlled to improve the memristor, set and reset voltage stability, and overcome low on/off current ratio. Different strategies can be used to control filament formation and rupture. Due to the fact that filament formation and rupture are primarily dependent on defects (such as gaps, vacancies, and inversions) within the perovskite matrix, the number of filaments that form and rupture in each cycle can be reduced by using a single crystal. Consequently, there is a crucial demand for a worldwide strategy to grow various high-quality single crystals by feasible methods. We first try to figure out the best and superior growing single crystal methods. Besides, grow-time needs to be optimized and shortened to facilitate future large-scale manufacturing. We thereafter prepare metal halide perovskite-based memristors.