Natural radon isotope is a classic geochemical tracer for oceanography studies. In this study, radon application as a powerful tool for quantitative estimation of many oceanographic processes will be introduced, such as submarine groundwater discharge (SGD), air-sea exchange, earth breathing process, etc. A device for radon in-situ measurement based on the principle of pulsed ionization chamber (PIC) was developed. This device realized the measurement and application of radon concentration in natural water bodies under multiple scenarios, such as unmanned ship navigation, and coastal wells, providing a strong technical support for the acquisition of radon data with high spatial and temporal resolution.