The invention discloses a downhole motor realizing efficient rock breaking by composite vibration impacts in order to solve the problems such as drill jamming, stick slip and low rock breaking efficiency in a deep well or an ultra-deep well. The technical scheme comprises that a metal motor rotor is connected to an anti-falling cap by threads, and a metal motor stator comprises a metal motor spacer rod and the metal motor rotor; a turbine stator and a turbine rotor are installed on a turbine assistant transmission shaft, and an eccentric wheel is fixed on the turbine assistant transmission shaft by a transmission pin; a main transmission shaft outer cylinder is connected on a main transmission shaft by a spline transmission set; a positioning bearing b is placed between the turbine transmission shaft and a cylindrical cam shell body; an upper cylindrical cam is fixed on the main transmission shaft, and a lower cylindrical cam is fixed on a punch hammer; a reset spring is clamped between the punch hammer and a cylindrical cam lower shell body; and a semi-ring is clamped in an anvil stand groove, and an all-direction sleeve is fixed on the cylindrical cam lower shell body and clamped between the cylindrical cam lower shell body and an anvil stand. The downhole motor realizing the efficient rock breaking by the composite vibration impacts disclosed by the invention can simultaneously generate stable high-frequency axial impacts and circumferential impacts in order to realize the composite vibration rock breaking.