Nanoscale PZT powder was prepared by SolGel method, CNT filler was surface modified with Fenton reagent combined with ultrasonic dispersion and ultraviolet irradiation; Hereafter, CNT modified Portland cementbased piezoelectric composites were prepared by mold pressing and DC polarization method. The test results of infrared spectrum and spectrophotometric show that when the ultrasonic temperature is 60 ℃ and ultraviolet rays irradiation time is 1 h, CNT uniformly disperses in aqueous suspension, the dispersivity reaches to its best. The microscopic test show that CNT and PZT disperse evenly in cementbased piezoelectric composite, but the structural density decreases. The piezoelectric constant and relative dielectric can reach up to 50.6 pC/N and 412.0, respectively, and compared with the same conditions for preparation of PZT cementbased piezoelectric materials, it increases up to 18.5%, 4.1%, respectively. Dispersed CNT fiber can play macroscope quantum tunneling effect, rendering that the composite is easier to polarization while hardly impairs its dielectric property.