The piezotronic effect is applied to modulate the physical properties of heterojunction electron gas and thus tune the electric transport in AlGaN/AlN/GaN heterostructure microwires. At room temperature, the conductance is increased by 165% under -1.78% compressive strains, and reduced by 48% under 1.78% tensile strains; at 77 K, this modulating effect is further improved by 890% and 940% under compressive and tensile strains, respectively.