In order to accurately measure the ammonia concentration in the broiler chamber during broiler breeding and precisely regulate the ammonia environment in the chamber, an active ammonia detection device, which was composed of a gas detection system, gas circulation system and auxiliary device, was designed. The device realized state switching by controlling the fan. The electrochemical ammonia module was used to detect the ambient gas. After the concentration data were analyzed and displayed by STM32 micro control unit (MCU), computational fluid dynamics (CFD) technology was used to simulate the velocity nephogram and velocity vector diagram of the device in different states. The time of each intake was determined by air age. In ammonia detecting, the air flow presented a counterclockwise circulation flow, which can make the ammonia concentration more uniform and the measurement results more accurate. The airflow velocity in the device was mostly about 2m/s and the maximum air age was 0.804s, so the single detection time was set to 1s. The device detected 6 times per minute and then took the mean value as the minute value. Through the field test in the broiler chamber, the results showed that the Pearson correlation coefficient between the ammonia concentration values detected by the active ammonia detection device designed and the ammonia transmitter was 0.832, which showed that the detected results were basically consistent, with an average difference of 3.46%. Generally, the fluctuation was smaller than that of the ammonia transmitter, and the measured value was more stable. The detection device had the advantages of fast speed, high stability, and low power consumption. It can be used as an ammonia detection device in the broiler chamber, and also can provide a theoretical basis and reference for the development and improvement of ammonia detection devices in the broiler chamber and other poultry houses.