This article improves the measurements of liquid viscosity coefficient with falling ball and gives an intensive study. We briefly introduce the experimental steps for measuring the viscosity coefficient of liquids using video analysis. It employs the open-source software Kinovea to record and track the falling process of a ball, excluding any unqualified experimental procedures and analyzing qualified experiments frame by frame. This method enhances the experimental measurement accuracy to 240 frames per second and reduces experimental error by at least 50%. Moreover we intensively study the effects of size and edge on the experimental results.