The submarine groundwater discharge (SGD) is not only an important part of the global water cycle, subterranean estuaries (STE) serve as the main areas of seawater—groundwater mixing, but also an important source and barrier of various chemical substances (dissolved carbon, nutrients, metals, etc. ) transported from land to sea as the main area of seawater and groundwater mixing. Strontium and its isotopes play an important role and are widely used in the study of chronostratigraphy, paleoclimate, paleoclimate and environmental pollution. The source terms of marine strontium flux mainly include rivers, SGD and submarine hydrothermal fluid, as well as a little rain and dissolved marine sediments; the sink of marine strontium flux is mostly buried in marine carbonate rocks, and a small part is exchange of submarine hydrothermal fluids. Strontium derived from SGD is also an important part of the modern marine strontium isotope budget. The study of SGD strontium transport and its effect on marine strontium budget is obviously insufficient. Based on the analysis of the sources of marine strontium in the world, the effects of SGD on marine strontium budget in the world were reviewed from the perspectives of the discharge process, research methods, strontium concentration and the distribution of n(87Sr)/n(86Sr) ratio. The geochemical behaviors of strontium and its isotopes in different lithologic aquifers were analyzed. The strontium concentration increases linearly with salinity in the horizontal direction, and the strontium element in the seawater recycling component is conservative on the whole; in the vertical section, it is found that strontium in groundwater of different STE strata also shows non-conservative addition, and the oxides of strontium and manganese change synchronously with the depth, but not with the change of iron oxides. Being Different from strontium concentration, the geochemical behavior of strontium isotope in STE is more complex. Since strontium isotope exchange and fractionation occur in underground estuaries, n(87Sr)/n(86Sr) values are typically non-conserved with the change of 1/Sr, but conserved mixing also exists. The different degree of strontium isotope exchange in the process of mineral adsorption/desorption is the main factor of the different distribution of strontium isotope in the aquifer. On the basis of available SGD flux and high-resolution global lithology data, more conservative and precise SGD strontium flux and isotopic composition are calculated: Global mean freshwater SGD mean strontium concentration is 4. 7 μmol/L, corresponding strontium flux is (1. 1~2. 4)×109 mol/a, n(87Sr)/n(86Sr) value is 0. 70892. Simultaneously, terrestrial fresh water SGD mixed with seawater in STE to form recycled seawater, and strontium isotope exchange occurred under the influence of biogeochemistry. Strontium flux of mixed SGD is (7. 0~15. 2)×1010 mol/a, corresponding n(87Sr)/n(86Sr)value being 0. 70910. Accounts for 4. 5%~9. 8% of marine strontium isotope budget. Strontium carried by SGD is an important part of marine strontium isotope budget is (4. 8%~10. 4%). At present, the marine strontium isotope budget is unbalanced, and SGD, together with the seafloor hydrothermal solution and its associated marine sedimentary rocks, constitute the source of radioactive strontium poor in marine strontium storage, and play the role of balancing radioactive strontium rich brought by rivers, which deepens the understanding and understanding of the impact of SGD on global marine strontium budget.