This paper presents a multi-axis control system of bar tacker. A bar tacker must meet the following requirements: feeding accurately, cutting automatically, needle stopping precisely and quickly, et ac. In order to achieve these functions, multi-thread synchronization control was introduced to ensure the multi-axis collaborative motion. And time-based PI method with velocity feed-forward was used to control the needle stop position. The software of this control system was programmed based on embedded Windows platform. At present this control system has been tested in the factory and the test results show that this method can accurately control the multi-axis motion and produce good sewing patterns. Besides lockstitch bar tacker, this control system can also be applied to other intelligent sewing machines by minor changes and improvement.