This article presents an active control method for electromagnetically induced transparency (EIT) in terahertz metamaterials. By integrating photoconductive silicon islands into the metamaterial unit cells, the transparency window can be significantly altered under the excitation of ultrafast optical pulses. This allows for optically tunable group delay in terahertz light, opening up possibilities for designing novel chip-scale ultrafast devices such as optical buffers and active filters. The active tuning of the EIT resonance is demonstrated through optical pump-terahertz probe (OPTP) measurements, with the modulation attributed to changes in the damping rate of the dark mode due to increased conductivity from photoexcitation. Theoretical calculations and numerical simulations support these findings, showing that the active EIT switching is caused by the suppression of the dark mode LC resonance. The ability to control the group delay in the EIT metamaterial is also demonstrated, with the optically tunable group delay showing promise for compact, controllable slow light devices.This article presents an active control method for electromagnetically induced transparency (EIT) in terahertz metamaterials. By integrating photoconductive silicon islands into the metamaterial unit cells, the transparency window can be significantly altered under the excitation of ultrafast optical pulses. This allows for optically tunable group delay in terahertz light, opening up possibilities for designing novel chip-scale ultrafast devices such as optical buffers and active filters. The active tuning of the EIT resonance is demonstrated through optical pump-terahertz probe (OPTP) measurements, with the modulation attributed to changes in the damping rate of the dark mode due to increased conductivity from photoexcitation. Theoretical calculations and numerical simulations support these findings, showing that the active EIT switching is caused by the suppression of the dark mode LC resonance. The ability to control the group delay in the EIT metamaterial is also demonstrated, with the optically tunable group delay showing promise for compact, controllable slow light devices.