According to the requirements of the electrical parameters of trigger voltage VS, switching current IS, hold current IH and VS, IH high and low temperature rate of change, the Silvaco-TCAD semiconductor device simulation software was used to complete the design of the transverse silicon controlled rectifier (SCR) discharge transistor with bidirectional low trigger voltage. The N- substrate, parasitic PNP transistor P- collector region, parasitic NPN transistor P- base region, N+ cathode region, N+ trigger region, parasitic PNP transistor P- collector region and parasitic NPN transistor P- base region spacing, parasitic NPN transistor base surface width are important structural parameters of the transverse SCR discharge transistor with bidirectional low trigger voltage, which have a significant impact on the triggering characteristics of the device. The effects of the above structural parameters on the output I-V characteristics and the resistance to transient current burn down of the device were analyzed in detail.According to the structure parameters of the device, the layout is drawn, and the process scheme of transverse SCR discharge transistor with bidirectional low trigger voltage was developed and trial-produced.Through the actual flow sheet, the key technology was solved, the VS, IS, IH, and VS, IH high and low temperature change rate of the developed sample sheet can fully meet the requirements of the electrical parameters.