The dock leveler is a bridge equipment used between forklifts and trucks to facilitate loading and unloading of goods. There are many classifications, generally divided into mobile boarding bridges and fixed boarding bridges. The loading and unloading platform is a very easy structure in the logistics site, which is the starting and ending point of the logistics chain of the enterprise, and a loading and unloading operation platform for the rapid and safe turnover of products and goods of the enterprise. The height of the loading and unloading operation platform is fixed, but the height of the carriage to and from the transport car is different, and a certain height difference or gap is always formed between the transport vehicle and the loading and unloading platform. As a result, the handling forklift cannot enter and exit the transport vehicle to directly load and unload the goods. Use boarding bridges to provide reliable connections. Enable forklifts to safely and quickly move in and out of transport vehicles for loading and unloading operations.