Abstract: The Bragg peak indicates the energy deposition characteristics of the charged-particle in a medium. The energy contribution and the monochromaticity of the charged-particle beams can be determined by analyzing their distribution and sharpness. The article introduces the design principle, performance testing and pilot use of a multi-anode gas ionization chamber, which can detect the Bragg peak generated in free air quickly. The voltage-current characteristics, the measurement repeatability and stability were all measured in a ⁹⁰Sr-⁹⁰Y β reference field. The primary experiment results indicate that the chamber has good saturation characteristic, repeatability and stability, and the measured range of α particle generated by ²⁴¹Am source is well coincided with the simulated results made by SRIM code.