The invention relates to a mechanical composite percussion boring speed increasing tool. The tool comprises a tool shell of which the inner portion is hollow, the bottom of the tool shell is fixedly connected with a drill bit seat, the tool shell is internally provided with a driving shaft capable of rotating under the impact of a fluid, the lower portion of the driving shaft is provided with an impact hammer circumferentially fixed and capable of reciprocating in an axial direction, and the lower portion of the impact hammer is provided with an impacting device capable of transmitting an axial impact load and a torsional impact load to the drill bit seat. The mechanical composite percussion boring speed increasing tool combines axial impact and torsional impact, and the composite impact effectively improves the rock breaking efficiency and prolongs the service life of a drill bit.