同步测量结构内部温度场及其厚度尺寸对准确评估高温设备的安全性和可靠性具有重要意义。为实现对高温结构内部温度场及其厚度的多参数同步在线无损测量，提出了同步测温测厚实验方案，发展了多参数交替迭代识别的数据处理方法，形成了高温结构内部温度和尺寸多参数同步测量的实验方法。针对20# 钢的超声探测实验结果表明：超声法与热电偶等方法的测量结果吻合较好，能够同步在线无损测量高温结构的内部温度场和厚度，具有精度高、可靠性好等优点。多参数同步测量的实验方法可为结构热安全评估提供更加准确的基准输入和评价依据，具有重要的工程应用前景。

Synchronous measurement of the internal temperature field and its thickness is of great significance to accurately evaluate the safety and reliability of high-temperature equipment. To realize multi-parameter synchronous online nondestructive measurement of temperature field and thickness in high-temperature structure, an experimental scheme of simultaneous temperature and thickness measurement was proposed, and a data processing method of multi-parameter alternating iterative identification was developed, which formed an experimental method of multi-parameter synchronous measurement of temperature and size in high-temperature structure. The experimental results of ultrasonic detection for 20# steel show that the ultrasonic method is in good agreement with the measurement results of thermocouple and other methods, and can simultaneously measure the internal temperature field and thickness of high temperature structure, with high precision and good reliability. The experimental method of multi-parameter synchronous measurement can provide more accurate reference input and evaluation basis for structural thermal safety evaluation and has important engineering application prospect.