The exploitation of the multi-functional property of the ferroelectric system has attained more interest recently. However, the morphotropic phase boundary (MPB) based high performance ferroelectric system implementations were limited in many applications. Here, the cost-effective solid-state reaction derived MPB based 0.3Ba0.7Ca0.3TiO3-0.7BaSn0.12Ti0.88O3 particles (BCST) applied as a bi-catalyst. The ferroelectric properties of the BCST system were studied, and it shows the 98% polarization retainability after 105 cycles. The ferroelectric BCST system, with the bandgap of 3.12 eV, was applied for photocatalytic and piezo-catalytic approaches to degrade the dye pollutants Methylene Blue (MB) and Rhodamine B (RhB). The prominent piezo-catalytic activity (k = 0.0195 min−1) in the RhB dye degradation than photocatalytic (k = 0.0078 min−1) approach ascribes to the high spontaneous polarization (Ps ≈ 12.66 μC/cm2) and piezoelectric coefficients (d33 ≈ 90 pC/N) of the BCST bulk material. The bi-catalytic activity improves the dye degradation rate (k = 0.04761 min−1)) of RhB, which is 610% of photocatalytic activity and 244% of piezo-catalytic activity. The main reactive species identified by the scavenger studies. The bi-catalytic activity on dye degradation remains almost the same after three cycles show clearly the excellent dye degradation stability of the BCST catalyst.