A water conserving reaming system includes a water storage box, a water pumping pipe communicated with the water storage box, a first lifting platform, a second lifting platform, a reaming mechanism assembly, and a reamer bit connected with a front end of the reaming mechanism assembly. The first lifting platform includes a first base, a lifting frame arranged on an upper portion of the first base and a pipeline joint. An end of the water pumping pipe extends into the water storage box. An other end of the water pumping pipe is communicated with a bottom portion of the first base. A filtering mechanism for performing primary filtering treatment on a water source from the water pumping pipe is arranged inside the first base. The second lifting platform includes a second base and a telescopic column arranged on an upper portion of the second base.