In food and biological laboratories and other fields, there are strict requirements for the number of planktonic bacteria, which further puts forward higher requirements for planktonic bacteria samplers. In order to solve the problem that the gas flow of the planktonic bacteria sampler are affected by the environment factors, the planktonic bacteria sampler with flow calibration function was researched in this paper, a venturi structure integrating atmospheric pressure and temperature & humidity sensors was designed, the flow compensation formula was improved, a fan control system based on anti saturation integral PID (proportion, integral, differential) was develop, and the real-time compensation and closed-loop control of the gas flow were realized. The VMD(Variational Mode Decomposition) algorithm was applied to filter the measurement data of atmospheric pressure, which reduced the influence of noise on the measurement results. A prototype of planktonic bacteria sampler based on Anderson impact principle was developed, and relevant experimental researches were carried out. The experimental results show that the differential pressure indication error of the instrument is within ±0.5% after calibration, and the flow collection accuracy indication error is within ±1%, which meets the requirements of the flow calibration specification of planktonic bacteria sampler, overcomes the problem of large gas collection flow error caused by environmental factors, and has good application value in the field of planktonic bacteria sampler.