Abstract: In order to solve the problem of determining the most critical parameter of the logging time of artificial well fluid resistivity logging, and get rid of the method that depends on the construction experience for a long time, guide logging technicians to obtain reliable logging curves, from the factors influencing the measurement time, the mass conservation law was used to build the calculation model for the best measurement time of logging, the computational formula for the best measurement time was derived, which was verified through in-site contrast experiment of boreholes. The results show that the computational formula set up by the model could provide reliable basis for selection of the measurement time of salinized logging and technical support for acquisition of the hydrogeological parameters of aquifers and aquicludes during the artificial well fluid resistivity logging and guide better the in-site hydrological logging.