This paper introduces a design method through the bandgap voltage to reduce the delay of IO, presents a design of IO with high speed, which meets the requirement of high speed SRAM products. The main design idea of this module is : With bandgap supplying a middle stage voltage，the module can response fast, which reduces the delay of IO. Through the HSPICE simulation results, the demand of 200 Mhz SRAM can be satisfied by this circuit, and the module has been proved reliable by taping out.