Lead magnesium niobate-lead titannate single crystal (abbreviated as PMNT) was used to fabricate PMNT/polymer 1-3-2 piezoelectric composite with different volume fractions of PMNT, by dicing single crystal PMNT along mutually perpendicular two directions on the surface and then filling polymer into grooves. The piezoelectric, dielectric and electromechanical properties of the novel composite were determined. It was demonstrated that a thickness electromechanical coupling coefficient of the composites could reach as high as 0.75 and acoustic impendence decreased to 14.9 Mrayls (lower than 30 Mrayls of PMNT). The pulse-echo waveforms of the composites without backing were also measured. It showed a -6dB bandwidth of 88% at the center frequency of 0.95MHz.