An adjusting device of lift lower beam safety tongs comprises a base and a lifting and pulling mechanism. The base comprises a working table and fixed bases fixed on the working table, the lifting and pulling mechanism comprises supports, a sliding shaft and a lifting and pulling bolt. The supports are installed on the two sides of the working table, the sliding shaft is installed between the supports, and the lifting and pulling bolt can move on the sliding shaft. The synchronism of the safety tongs is further adjusted through the design, the adjusting device not only is visual, but also is simple and clear, good commissioning of the safety tongs is performed maintaining and overhauling are convenient before the safety tongs are applied to a lift, so that potential safety hazards caused by asynchronism of the safety tongs are effectively and conveniently avoided before the application, and normal and effective using of the safety tongs of the whole lift is facilitated.