For more than 20 years, the thermal mass flow meters have been widely used in several industries such as the petroleum refining industry, waste water processing and steeling making industry. I will call it “TMF” in the rest of the article. The TMF’ low-flow sensitivity and fast response have made them the first choice for many critical gas flow application. However, there are still some inadequacies in the TMF. Such as interruption among the wires, high cost of the installation and influenced by temperature. Some of the problem comes from its way of the connection--- four-wire connection. Two-wire connection can resolve some of these problems. In this thesis, the author presents a new type of two-wire installation and use of TMF which can be realized low production cost. The author found a new measurement method, which is detecting the functional relationship between working current of a traditional TMF and the flow. The author also designs a measurement converter needed for adequate signal processing so that flow value measurement values can be shown in computers.