Abstract: To address the urgent demand for multi-field cooperative control of temperature, pressure, and atmosphere in the nano-silver sintering process for SiC power module packaging, a high-precision nano-silver sintering system has been designed and developed. The system adopts a cooperative control framework combining zoned straight-tube heating and pneumatic pressurization, together with closed-loop low-oxygen atmosphere regulation, to realize precise matching and dynamic stability of key process parameters in the sintering process. Experimental results show that under typical process conditions of 230 °C and 25 MPa, the system achieves a temperature uniformity better than ±3 °C, a pressure uniformity better than ±3%, and stably controls the chamber oxygen content below 50 μL/L. Its comprehensive performance is significantly superior to that of existing similar systems. The high consistency of the pressure and temperature fields is verified using pressure-sensitive paper and multiple thermocouple temperature measurements. Ultrasonic and computed tomography inspections further demonstrate that the prepared SiC/AMB joint interfaces exhibit low porosity and reliable connection quality. Finite element simulation reveals the distribution characteristics of higher stress at the chip edges and lower stress in the central region during sintering, providing a theoretical basis for process optimization. In this research sintering system with excellent comprehensive performance is developed, and an important breakthrough in atmosphere control and multi-field coupling methods is represented, thereby providing a reliable process platform and technical support for the packaging of high-performance power electronic devices.