The present application provides a joint replacement surgical robot navigation and positioning system and method. The system includes a preoperative planning module, which is used to: perform segmentation and reconstruction for a hip joint to obtain a three-dimensional model of the hip joint according to obtained medical image data of the hip joint, and carry out a preoperative planning to determine a surgical scheme according to the three-dimensional model of the hip joint; an optical navigation and positioning module, which is used to: generate a navigation instruction according to the surgical scheme, register the three-dimensional model of the hip joint to obtain a hip joint entity model according to spatial position relationships among an optical positioning device, a hip joint of a patient and a surgical probe, match the hip joint entity model with the preoperative planning model, and determine a surgical position on a bone of the patient according to the hip joint entity model; and a mechanical arm control module, which is used to: move an end effector to the surgical position on the bone of the patient, and control the end effector to perform osteotomy, rasion, and press-fitting operations on the hip joint according to the navigation instruction. Preoperative planning is executed through the orthopedic surgical robot, surgical operation is completed at a high level, the operation intensity of surgeons may be greatly reduced, the operation time is saved, and the operation accuracy is improved.