Based on the principle of manual preparation of sclerosing foam with Tessari method, using the analysis of user requirements and combining it with theory of mechanics, we designed an automatic equipment. The device could be used to replace the manual operation, and could overcome the shortcomings of manual sclerosing foam preparation, such as the difficulty in controlling of pushing speed and stroke and poor reproducibility. This automatic device has the functions of adjustable pushing speed, pushing frequency, pushing stroke and is suitable for a variety of different types of syringes. It can not only provide quantitative parameters for the study of foam properties, but also be used for the standardization of clinical sclerosing foam. The experimental study on "the effect of pushing speed on the stability of foam" was carried out with using the device, and the experimental results were quite satisfactory.