This instrument is an essential tool for regular energy efficiency testing of industrial boilers and thermal efficiency measurement during energy-saving diagnosis of boilers. The tester is designed to address the shortcomings of current boiler energy efficiency testing, which lacks specialized instruments, requires multiple instruments for parameter testing, and manual calculation of boiler thermal efficiency. Drawing on the characteristics of similar foreign instruments, it is a specially designed instrument that integrates multiple parameter measurements, comprehensively analyzes and automatically calculates boiler thermal efficiency based on measurement and input parameters. Measurable flue gas dynamic pressure, flue gas static pressure, pressure before flowmeter, temperature before flowmeter, flue gas temperature, moisture content, flue gas composition O2 SO2、CO、NO