The invention provides a regulation device of a melt flow thermal field for producing a large-width cast-rolling plate. The regulation device comprises a heat insulation part and a regulation device body. The heat insulation part comprises a plurality of heat insulation single bodies. The regulation device body comprises temperature control equipment and flow regulation equipment, and the temperature control equipment is arranged on the flow regulation equipment. The heat insulation part is arranged inside a front box body and divides the front box body into a plurality of cavities through the heat insulation single bodies. The regulation equipment is arranged in the cavities, and forms a channel with the heat insulation single bodies and the bottom of the front box body, and the channel is communicated with an inlet and a casting nozzle of the front box body. The regulation device is concise in overall structure and low in production cost, the heat insulation single bodies are used for forming the channel structure in a dividing mode, the temperature control equipment and the flow regulation equipment are included, when melt flows to the channel, the melt can be divided into a plurality of strands, the temperature and the flow velocity of all the strands of melt can be well regulated according to actual needs, and therefore the entire flow thermal field of the melt is even and stable.