<p>Developing high-performance, lead-free piezoelectric ceramic is crucial for achieving global sustainability in electronic materials, particularly for harsh-environment sensing. Bismuth layer-structured ferroelectric calcium bismuth titanate (CaBi₄Ti₄O₁₅), with its high Curie temperature <i>T</i>_C of 790&#xa0;℃, is a promising candidate. However, its widespread application is limited by inherently weak piezoelectric activity and energy-intensive conventional sintering process, which also causes bismuth volatilization. A synergistic strategy of manganese doping and microwave sintering (MS) was developed to fabricate CaBi₄Ti₄O₁₅ ceramics. The rapid MS process provides a green alternative, reducing energy and time. The optimized ceramic achieves a piezoelectric coefficient <i>d</i>₃₃ of 24.4 pC/N, triple that of the pristine CaBi₄Ti₄O₁₅, while maintaining a high <i>T</i>_C of 784&#xa0;℃. It exhibits excellent thermal stability (&lt; 5% <i>d</i>₃₃ variation up to 600&#xa0;℃) and a two-order-of-magnitude increase in high-temperature resistivity. This work demonstrates that combining defect engineering with rapid, low-carbon manufacturing enables environmentally benign, high-performance piezoelectrics for extreme environments.</p> Graphical abstract <p></p>