Abstract: To establish the high-pressure ionization chamber products for dose rate monitoring of the environmental level γ ray, the design from the aspects of ionization chamber shell, detector, electronic system, etc. are optimized, to improve the environmental adaptability, electromagnetic compatibility and reliability of the equipment. According to the standard method, the general quality characteristics test was carried out at a third party. The test results showed that the working and storage temperature range of the product was -10 ℃-45 ℃; Humidity range ≤93% RH; It has certain anti-vibration and impact capacity, and meets the requirements of the severity level 2M1 of transport environmental conditions in GB/T 8993—1998; Electrostatic discharge immunity and radio frequency electromagnetic field radiation immunity in electromagnetic compatibility shall meet the relevant requirements of GB/T 17626-2—2018 and GB/T 17626-3—2016; The reliability meets the requirement of MTBF≥1 000 h. The environmental adaptability, electromagnetic compatibility and reliability of this product meet the requirements of meter-level products. It can be used as a portable radiation dosimeter in climatefree places. High pressure ionization chamber can be used as a high accuracy work measuring instrument for ambient level air kerma to carry out radiation dose monitoring.