Aiming at the problems of low efficiency, high cost, equipment disassembly requirement and potential equipment damage in traditional calibration methods for temperature scanning valves, this paper proposes a fully automatic in-situ calibration method based on a "four-layer architecture". A fully automatic in-situ calibration system for temperature scanning valves was constructed, adopting a four-layer architecture design consisting of standard signal layer, signal switching layer, data acquisition layer, and control and analysis layer. By using dedicated metering aviation plugs, on-site calibration was realized, eliminating the equipment disassembly and assembly steps required in traditional methods. Systematic parameter optimization experiments were performed, in which four key parameters including measurement time, data acquisition interval, two-point calibration standard value combination, and channel switching stabilization time were comparatively analyzed, and the optimal parameter configuration balancing accuracy and efficiency was determined. A fully automated calibration workflow was developed, enabling complete automatic execution from equipment connection, data acquisition to coefficient calculation and writing, which simplifies the operation process and reduces errors. The results show that under the optimal configuration (measurement time of 8 s, data acquisition interval of 250 ms, calibration standard values of (10 mV, 40 mV), and channel switching stabilization time of 3 750 ms), the measurement repeatability (standard deviation) of the system is 0.003 3 mV, corresponding to an equivalent temperature error of 0.083 ℃, which meets the requirement of an error not exceeding ± 0.5 ℃. The proposed calibration method provides a reliable metrology support for the engineering application of temperature scanning valves.