Abstract: In order to optimize the design of tissue-equivalent proportional counter (TEPC), the electric field distributions in two kinds of optional construction counters were simulated by Maxwell software, and the configuration of counter consisting of the cylinder with field tubes was primarily confirmed. Based on the simulation detector configuration, a gas-flow TEPC was designed and constructed in order to research the electric field distribution characteristic. Finally, TEPC device was developed and the electronic noise level was measured. The experiment results indicate that the electronic characteristics of detector could satisfy the radiation measuring requirement.