Abstract: This paper introduces a design of multifunctional automatic verification system for heat meters with various diameter, and it consists of hot water flow detection system, temperature detection system, data detection system and automatic control system.During detecting process, hot water flow detection system provides circulating water for the test line. Temperature detection system simulates actual inlet and outlet temperature. Data detection system and automatic control system collect flow rate, temperature and other signals during the verification process. According to thermodynamic formulae, the system realizes its verification by calculating the standard heat value and comparing it with heat value of verified heat meter. Experimental results show that the system can conduct the heat meter verification well automatically and manually. The verification system meets the design requirements, realizes the real-time monitoring, record saving, report printing and other functions. The system has the characteristics of a higher degree of automation, more verifying channels and higher flexibility.