Compared with Pb(Zr,Ti)O<sub>3</sub> (PZT) ceramics, piezoelectric ceramic composites (PCCs), and piezoelectric polyvinylidene fluoride (PVDF) polymer, piezoelectric single crystal composites (PSCCs) are thought to be the promising candidates for hydrophone applications because of their superior hydrostatic performance. However, due to the brittleness and small dimensions of single crystals, the preparation of large-area or conformal PSCCs is to be challenged. Herein, we prepared a large-area PSCC with dimensions of 50 mm <inline-formula> <tex-math notation="LaTeX">$\times \,\, 50$ </tex-math></inline-formula> mm <inline-formula> <tex-math notation="LaTeX">$\times \,\, {5}$ </tex-math></inline-formula> mm using 3-D-printing-assisted dice-and-insert technology. The hydrostatic piezoelectric performances for PSCC were investigated using a quasi-static method. The hydrostatic figure-of-merit (HFOM) of PSCC is approximately <inline-formula> <tex-math notation="LaTeX">$1469\times 10^{-{15}}\,\,\text{m}^{{2}}$ </tex-math></inline-formula>/N, which is higher by 69.4% than that of PCC. Furthermore, PSCC shows advantages in the dielectric loss, frequency constant, electromechanical coupling coefficient, and hydrostatic pressure stability. The results suggest that PSCCs have great potential in substantially improving the sensitivity of hydrophones. In addition, 3-D-printing-assisted dice-and-insert technology breaks through the restriction of as-grown piezoelectric crystal size so as to make it possible for the applications where large-scale piezoelectric composites are required.