Flowmeter is an advanced instrument for on-line measurement of fluid flow in pipeline. It is widely used in petroleum, chemical industry, papermaking, metallurgy and other industries, and continues to develop in the direction of intelligence. This paper introduces a new intelligent flowmeter developed with msp430f449 single chip microcomputer. Its basic principle is: relying on the rotation of components, the electric pulse signal is generated by photoelectric encoder or magnetic sensor, and sent to the flow calculation device composed of single chip microcomputer for processing. The flowmeter adopts new intelligent instrument technologies such as data correction, digital filtering, multi output form, self diagnosis and power failure protection, as well as dual power supply system and dual sensor technology, so that it can more adapt to various complex working environments.