Reamer with self-centralizing and guiding functions

The invention provides a reamer with self-centralizing and guiding functions. The reamer includes a spindle, a plurality of gear wheels, a plurality of centralizing ribs, one or more gear wheel reinforcing ribs, a base and a centralizing barrel, wherein the base and the centralizing barrel are successively fixed to the spindle in a sleeving mode, the spindle includes a first medium flow channel, asecond medium flow channel and a shaft body, and the base is provided with an inner cavity, a plurality of gear wheel seats and third medium flow channels with the number equal to that of the multiple gear wheel seats; the multiple gear wheels are fixedly arranged on the multiple gear wheel seats, and the one or more gear wheel reinforcing ribs are arranged on the right side of the base and are capable of connecting the base or each gear wheel and the shaft body of the spindle; the centralizing barrel is hermetically and fixedly connected with the left side of the base and part of the shaft body of the spindle to for