A combined down-the-hole hammer, characterized in that, the hammer comprises: a coupler connected with a drill rod and internally provided with a first gas passage; a bracket; a plurality of impactors installed on the bracket, each of the impactors being provided with a second gas passage; when the combined down-the-hole hammer being driven by the power head to rotate and drill, an impact drill bit of each of the impactors being rotatable around its axis; a gas distributor which is provided between the coupler and the bracket; the gas distributor is provided with a gas collection chamber communicated with the fist gas passage and a plurality of gas-distributing paths communicating the gas collection chamber with the second gas passage of each of the impactors; the coupler comprises a columnar connector which forms the first gas passage; the drill rod is provided with an installation hole matched with the columnar connector; the columnar connector and the drill rod are connected by a pin shaft running therebetween; a sealing structure is provided between the columnar connector and the installation hole; each impactor comprises: an impactor main body installed in the interior of the bracket, the impactor main body being internally provided with a piston cavity for installing an impact piston; and an impact drill bit installed at the lower end of the piston cavity, the impact drill bit being matched with the impactor main body and being movable axially and rotatable circumferentially; the impact drill bit comprises an impact head and a guiding axis connected with each other; the upper portion of the guiding axis is provided with a limiting concave portion extending axially; a limiting ring is sleeved around the limiting concave portion; the guiding axis is inserted into the piston cavity and the limiting ring is limited by a locating platform provided on the inner wall of the piston cavity and a guiding sleeve installed at the lower port of the piston cavity; the guiding sleeve is sleeved on the guiding axis. a coupler connected with a drill rod and internally provided with a first gas passage; a bracket; a plurality of impactors installed on the bracket, each of the impactors being provided with a second gas passage; when the combined down-the-hole hammer being driven by the power head to rotate and drill, an impact drill bit of each of the impactors being rotatable around its axis; a gas distributor which is provided between the coupler and the bracket; the gas distributor is provided with a gas collection chamber communicated with the fist gas passage and a plurality of gas-distributing paths communicating the gas collection chamber with the second gas passage of each of the impactors; the coupler comprises a columnar connector which forms the first gas passage; the drill rod is provided with an installation hole matched with the columnar connector; the columnar connector and the drill rod are connected by a pin shaft running therebetween; a sealing structure is provided between the columnar connector and the installation hole; each impactor comprises: an impactor main body installed in the interior of the bracket, the impactor main body being internally provided with a piston cavity for installing an impact piston; and an impact drill bit installed at the lower end of the piston cavity, the impact drill bit being matched with the impactor main body and being movable axially and rotatable circumferentially; the impact drill bit comprises an impact head and a guiding axis connected with each other; the upper portion of the guiding axis is provided with a limiting concave portion extending axially; a limiting ring is sleeved around the limiting concave portion; the guiding axis is inserted into the piston cavity and the limiting ring is limited by a locating platform provided on the inner wall of the piston cavity and a guiding sleeve installed at the lower port of the piston cavity; the guiding sleeve is sleeved on the guiding axis.