Abstract: The traditional experiment device of measuring liquid viscosity coefficient by falling ball method is improved by Hall speedtrap device in this article. The reformed viscosity coefficient measuring device can realize accurate measurement for various liquid viscosity coefficient by rising ball method and falling ball method, including transparent liquid and opaque liquid. Compared with the traditional measuring device, the improved device not only improves the accuracy of experimental result, broadening the range for measurement, but also contributes to the cultivation of innovative and practical talents, speeding up the construction of new engineering disciplines.