In this study, the anti-chiral negative Poisson's ratio structure BaTiO3 piezoelectric ceramics were fabricated by vat photopolymerization 3D printing technology, which obtained an ultra-high transverse piezoelectric coefficient d31. Here, we performed uniaxial compressive load simulations and electric field-driven lattice in-plane strain response simulations, which showed an in-plane negative Poisson's ratio of −1 for the BaTiO3 ceramics. Its strain amplification is about 10 times that of BaTiO3 bulk material. Using the principle of positive and negative piezoelectric effects, we measured effective transverse piezoelectric coefficients d31 for different dimensional parameters. The effective transverse piezoelectric coefficient d31 with a maximum of 599 pm/V was detected at a ligament aspect ratio of 3.6 for the negative Poisson's ratio BaTiO3 piezoelectric ceramics, which is 7.7 times higher than that of the bulk material. For the prepared hydrophone, test results show that the effective hydrostatic strain constant dh and Hydrostatic Figure of Merit (HFOM) of BaTiO3 piezoelectric ceramics with a negative Poisson's ratio structure are 29.6 and 808 times higher than those of bulk BaTiO3.