Abstract: All-optical switches have been studied for 40 years, but still do not fully meet the technical requirements for practical optical switching devices. In recent years there has been much interest in all- optical switches with silicon- based nanowaveguide microcavity, fabricated from silicon-on-insulator materials through mature CMOS processes，working at optical communication wavelength; this has greatly promoted the development of practical all- optical switches. This paper will review five types of these switches, including the ridge and groove nanowaveguide types, the ring resonator and FP cavity microcavity types, as well as the working principle of optical nanowaveguide, photonic crystal, and surface plasmon. Their common characteristics and results of past investigations are analyzed and summarized, in the hope of promoting future research in this field in China.