As a radioactive gas geochemical survey method, soil radon measurement can be affected by a lot of interference. If we do not pay attention to these interference factors while testing, interference and abnormal phenomena will be observed; these present great difficulties while analyzing the data. The P2000 is portable, battery-powered, and easily operable. It can be used for field observation, anomaly verification, and the measurement of soil radon concentration for seismic subsurface fluid observation. In this study, based on soil radon concentration measurements using the AlphaGUARD P2000 portable radon monitor, we analyze the gas recovery conditions and influencing factors, discuss the soil radon determination method, and try to identify related factors that influence soil radon measurement.