In recent years, the seismological community has seen an amazing increase in the amount of seismic arrival time picks with the help of artificial intelligence. But, the accuracy of this data remains a challenge to seismologists. In comparison with automatic picks, manual picks have sufficient reliability and accuracy because manual picks are often used not only as a benchmark to evaluate automatic picking algorithms, but also as training samples to train artificial intelligence models. However, measurement through manual labor is a laborious and time‐consuming task. To alleviate the manual labor involved in measuring phase arrival time, we developed a graphical interface named Tcl/Tk Interface for Measuring Crustal Phase‐Onset Time (TIMCPOT). The TIMCPOT is mainly equipped with two modules: one is designed for measuring seismic arrival time, and the other is for relocating hypocenter. TIMCPOT simplifies user interaction with seismic data, thus reducing most manual labor. TIMCPOT provides several graphical workflows to carry out detection, identification, revision, and comparison operations on measurement work. The measurement procedure can be operated either manually or by autopicker. For the sake of allowing the user to interact easily with seismic data, TIMCPOT is designed to be executed in a semiautomatic model during several necessary procedures such as visually inspecting results and manually modifying picks. By applying a near real‐time displaying technique, TIMCPOT can create a travel time curve figure and comparison chart for manual picks in a timely fashion, which provides a rapid way to estimate data quality. The measurement efficiency and travel time data quality have been significantly improved using this graphical interface. An explicit demonstration was shown to validate the powerful performance mentioned earlier. The primary advantage of TIMCPOT is that it reduces manual labor while retaining valuable manual experience on measuring phase picks. Of course, TIMCPOT has several limitations. However, most limitations will be improved in future development.