The utility model belongs to the technical field of tight oil horizontal well volume fracturing construction and particularly provides a large displacement integrated fracturing high-low pressure manifold device. The large displacement integrated fracturing high-low pressure manifold device comprises a high-pressure manifold set and a low-pressure manifold set and is characterized in that the high-pressure manifold set is located over the low-pressure manifold set, and the high-pressure manifold set and the low-pressure manifold are fixed to a manifold sledge; the high-pressure manifold set is of an II-type double-pipeline structure formed by a pipeline A and a pipeline B, and the low-pressure manifold set is of an I-type structure and is formed by a transverse pipe and longitudinal pipes connected to the two ends of the transverse pipe. According to the large displacement integrated fracturing high-low pressure pipe manifold device, liquid is well supplied to 10-14 fracturing trucks by a single tight oil horizontal well volume fracturing blender truck, far-end transmission and energy-accumulation supply of the discharge displacement and discharge pressure of the fracturing blender truck are achieved, and the defects that the single fracturing blender truck is insufficient in discharge assembly pressure and far in discharge liquid supply pipeline are overcome; the number of connection of field high-pressure pipelines is reduced, well mouth high-pressure low-resistance injection of 10 m<3>/min displacement is achieved, and pipe wall friction resistance and potential scouring safety hazards are greatly reduced.