A kind of measuring instrument for liquid viscosity coefficient using 3D laser positioning and temperature controller was introduced. The measuring device uses the three horizontal and one vertical placed laser photoelectric gates on the measuring cylinder to realize three-dimensional precise positioning of falling steel beads, the drop of small steel beads along the central axis of measuring cylinder, and precise measurement of falling time of steel beads. One can measure the liquid viscosity coefficient at different temperature using the temperature controller. The new measuring device has the characteristics of intuitive experimental process, simple operation, accurate measurement data and good repeatability. The instrument can be useful in scientific research and general physics experiment teaching.