The invention belongs to the technical field of oil and gas exploitation, and particularly relates to a long pipeline pipe friction resistance testing device and method. The device comprises a friction resistance testing system and a liquid preparation sand conveying system. The method uses the friction resistance testing system, the pressure difference of a sample liquid or a sand-carrying liquidand water flowing through a tested pipe at different pump speeds is measured, and a resistance-reducing ratio is further calculated. The friction resistance change law and the resistance-reducing ratios under conditions such as different pipe diameters, construction parameters and fracturing fluid types can be tested and evaluated accurately, reasonable construction parameters are provided for fracturing design, and the pertinence and the reliability of the fracturing design are improved.