An electronically controlled terahertz amplitude modulation device is designed and implemented by integrating silicon-based microstructure with vanadium dioxide phase-change film. This device has a high transmittance of terahertz waves and very low insertion loss of the device, while having a large operating bandwidth and modulation depth. Simulation and experimental results show that the modulator's response bandwidth for the increased transmission effect of terahertz waves is 0.25-0.95 THz. The transmission of the modulator is over 80% in the frequency range of 0.4-0.85 THz, and compared with the transmission of high resistance silicon wafer, it is increased by over 10%. And the transmittance of the modulator can be up to 85%. After the device is electrically controlled, the modulation depth can reach more than 76%，and the change range of the modulator's transmittance can reach 65%. An important application value of the THz modulator is demonstrated in terahertz imaging and communication system, because of its low insertion loss, large modulation amplitude and wide working bandwidth.