Abstract: As a non-contact measurement technique,ultrasonic flow measurement has a good prospect of application in industrial production and daily life.A kind of transit-time ultrasonic flowmeter is designed by adopting the 16-bit MSP430F447 MCU and the high precision interval measurement chip TDC_GP2 with a precision of 50ps.TDC_GP2 has the function of temperature measurement,so it can automatically compensate for the error cased by temperature changes in the measurement procedure.The flow rate and total flux can be shown on the LCD device.The flowmeter can be managed by the upper-monitor in large application via communication module.The experimental results show that it is a practical flow measurement instrument with improved functions,low power consumption,high precision and high stability,and it is very fit for liquid measurements,such as oil and water.