Microgrid is a unity composed of distributed generation, energy storing devices and load. As the penetration of distributed generation increasing, microgrid application domain is more extensive. Some problems often occur in microgrid, such as parallel inverter power distribution imbalance, harmonic pollution, series parallel resonance, fault current and inrush current. Virtual impedance technology which is achieved easily can change the impedance characteristics of grid-connected inverters and solve the above problems effectively, hence this technology has broad application prospects. This paper comprehensively introduces the application scenarios of virtual impedance and corresponding implementation methods, combined with adaptive virtual impedance that is the current hot research topics, and discusses the future research trends and key issues that may be encountered. This work is supported by National Natural Science Foundation of China (No. 51677066).