介绍了以ＭＣＳ－５１单片机８０３１为核心的集中供热系统中各支路管线在线热平衡测试智能仪表的硬件和软件的组成，以平衡阀口径－压差－流量曲线为参考，建立了在不同压差状态下流量测试的数学模型，对十几个供热管线测试表明，与进口的超声波流量仪对比，最大测量偏差＜１０％，测试条件宽松，适于野外作业。 This paper introduces the composition of the hardware and software of on-line thermal balance test intelligent instrument of each branch pipeline in central heating system with MCS-51 single-chip microcomputer 8031 ​​as the core. Taking the balance valve diameter-differential pressure-flow curve as reference, The mathematical model of the flow test under poor conditions shows that the maximum measurement deviation is less than 10% compared with the imported ultrasonic flowmeter and the test conditions are loose and suitable for field work.