The invention provides a crankshaft pressure straightening device integrating journal roundness detection. The crankshaft pressure straightening device integrating journal roundness detection is used for detecting the roundness of a journal and straightening the deformed portion of a crankshaft. The crankshaft pressure straightening device integrating journal roundness detection is characterized by comprising a supporting portion, a driving portion, a detecting portion and a straightening portion, wherein the supporting portion comprises a fixed plate, supporting plates, a supporting rod and a connecting rod, the driving portion is used for driving the crankshaft to rotate and comprises a motor arranged on the fixed plate and a chuck, the center portion of one side face of the chuck is connected with the output end of the motor, the detecting portion is used for detecting the bending deflection of the crankshaft and the roundness of a main journal and comprises a first displacement sensor arranged at the top end of the connecting rod, second displacement sensors, third displacement sensors and a torque sensor, each supporting plate is provided with the corresponding second displacement sensors and the corresponding third displacement sensor, the torque sensor is arranged on one side face of the chuck, and the straightening portion is used for straightening the deformed portion of the crankshaft and comprises a hydraulic cylinder arranged on the supporting rod, a pressing plate arranged at the output end of the hydraulic cylinder and a pressure sensor arranged at the upper end of the pressing plate.