As a new solution raised in recent years of optical switches, Semiconductor microring resonator device has its advantages in low-power consumption, ultralow-latency, ultracompactness. Other research groups have proposed many valuable schemes on microring resonator optical switch. We analyzed the characteristic of the microring resonator based on its theory and structure. Depending on the latest research progress, we introduce the use of the microring resonator as switches. We also discuss the emphasis which need to be further improved and the perspective of the microring resonator as ultralow-latency optical switches.