A fast turn-on low-trigger improved DTSCR (MDTSCR) was proposed. Based on the traditional DTSCR, the MDTSCR added a current gain amplifier module, which greatly had improved the current gain of the parasitic bipolar junction transistor, reduced the trigger voltage, and improved the opening speed of the device. The experimental results showed that, compared with traditional DTSCRs, the turn-on time of the MDTSCR was reduced by 52%, and the trigger voltage was decreased from 5.5 V to 4.5 V under a 28 nm CMOS process. The MDTSCR achieved a best protection performance by adjusting the number of diodes to adapt to the different design windows at 28 nm CMOS process.