Traditional test equipment struggles to meet the high-precision and efficient static temperature testing requirements of thin-film thermocouples in high-temperature environments. To address this issue, a chamber furnace with large-space and precise temperature control functions has been developed. The furnace body adopts a split-type multi-layer structure design. Its side thermal insulation components can be flexibly disassembled to eliminate installation obstructions, satisfying the testing needs of thin-film thermocouples with different shapes. High-efficiency heating is achieved using three-section molybdenum disilicide heating elements, combined with a water-cooling system to realize precise temperature control and generate a stable and reliable temperature field. A three-dimensional thermodynamic model was established and simulated using ANSYS Workbench 2019R3 software. The simulation results show that the temperature field at the measuring end and the temperature at the reference end of the sample meet the design expectations. Practical tests conducted with the developed box-type furnace indicate that the temperature fluctuation in the furnace's test coordinate system is 0.47 ℃ / 6 min, and the temperature field uniformity is better than 3 ℃ / 50 mm, which complies with the testing requirements for thin-film thermocouples. Tests on Au-Pt thin-film thermocouples were conducted using this box-type furnace, further verifying its application effectiveness. It provides important technical support for the static temperature characteristic detection of thin-film thermocouples.