Abstract : With the rapid development of new welding technologies and products, the requirements for welding quality are becoming increasingly stringent. The weld seam and HAZ, as weak points in the joint, have received considerable attention. The composition, microstructure, and properties of the weld seam are mainly determined by the welding chemical-metallurgical process, which is a non-equilibrium physicochemical-metallurgical process. This non-equilibrium is caused by the local heating of the welding heat source and the characteristics of the quasi-steady temperature field. Therefore, monitoring the temperature changes at multiple points in the heat-affected zone during welding is extremely important. This paper uses LabWindows/CVI software as the software development platform to develop a software system for real-time acquisition of multi-channel welding thermal cycle data. The development of this software is of great significance for understanding stress deformation, welding cooling phase transformation processes, joint microstructure, and improving welding quality. It also serves as an important basis for formulating, evaluating, and optimizing welding processes. Keywords: Welding thermal cycle; Data acquisition system; LabWindows/CVI 1. Introduction In welding production processes and scientific research, the measurement of welding temperature is an important research aid. Welding is a process of uneven heating and cooling, which can also be called a special heat treatment, resulting in uneven structure and properties in the heat-affected zone of the weld. At the same time, it will generate complex stress and strain. The temperature field of the welded workpiece determines the welding stress field and strain field, which are the main factors affecting welding quality and productivity [1, 2]. Therefore, it is extremely important to monitor the temperature change of the heat-affected zone during the welding process. Xu Xiangyang et al. [3] of the Department of Mechanical Engineering of North China Electric Power University designed a welding thermal cycle tester composed of a single-chip microcomputer 8031. The tester can collect, process and display welding temperature signals, and can print out welding thermal cycle curves and characteristic parameter values. The hardware circuit of its test system consists of a single-chip microcomputer, thermocouples, numerical circuits, analog circuits and peripheral circuits. Qi Wenjun et al. of Xinjiang Institute of Technology[4] developed a microcomputer-controlled dynamic testing instrument, which consists of a sensor-K type (nickel-chromium-nickel-silicon) thermocouple, filter, OP27 high-precision operational amplifier, analog-to-digital converter-MC14433, opto-isolator, single-chip computer and power supply. Dynamic testing of the welding thermal cycle of 3mm low carbon steel thin plate was carried out, and the temperature distribution curve was plotted. At the same time, the mathematical model of the temperature field under the same conditions was established by applying the welding heat transfer theory, and the welding temperature distribution curve and thermal cycle characteristic parameters were calculated. The above studies all use single-chip to form thermal cycle testing equipment, which does not make full use of the advantages of microcomputer in data processing, and fails to further analyze and process the collected data. In addition, the main parameters of welding thermal cycle can also be calculated using the mathematical model derived from welding heat transfer, but this calculation process is cumbersome and has large errors, making it difficult to obtain accurate data. The rapid development of computer hardware and software has provided new methods and approaches for welding thermal cycle testing. Therefore, developing a software that can monitor the temperature change of the heat-affected zone within a certain time during welding through virtual instruments has very important practical value. Download the full text of the software design for a multi-channel welding thermal cycle detection system