The invention discloses a method for indoors measuring injected water salinity of carbonate reservoir low-salinity water drive. The method comprises following steps of measuring content of calcite ordolomite in multiple sets of different carbonate rock, and the salinity of multiple sets of saline with different kinds of salinity; in the multiple sets of saline with different kinds of salinity, measuring the initial wetting angle and the final wetting angle of each set of same carbonate rock and an oil drop, and obtaining the maximum variation of the wetting angle; applying a least square method to fit out the functional relation between the maximum variation of the wetting angle along with changes of carbonate rock components and saline salinity; and measuring the content of calcite or dolomite in target carbonate reservoir rock, and according to the above functional relation, calculating the salinity value when the maximum variation of the wetting angle is the maximum value. The salinity value is the injected water salinity suitable for target carbonate reservoir low-salinity water drive. The method can conveniently, rapidly, and accurately obtain the optimal salinity of the carbonate target reservoir water drive development.