Todays, transportation and logistics engineering process are among the important issues of organizations in the competitive market. Considering the logistical structure of the logistics engineering and the more attention paid to the logistical tools and, in particular, such as the use of these tools, such as containers (pallets, containers, etc.), transportation equipment (trailer, forklift trucks, etc.), and The art of building the supply and distribution network with respect to the main warehouses, cross dock and temporary storage, is one of the most important and contemplative cases. In fact, all these tools work together to maximize system efficiency in the field of logistics with respect to the main impact indicators, including the time of shipment (loading, disloading, the allocation of trailers, etc.). The main goal of this paper is to present and develop a mathematical model of trailer schedule planning in possible conditions in the cross dock. In fact, the main function of this mathematical model is to minimize the total time of the logistics process from the stage of emptying the pallets from the  materials producers in the cross docks and assigning the trailer to the door and finally reloading the pallets to be distributed to the production sites. . To solve this model and to analyze the outputs, mixed integer programming was used by GAMS software.