The invention relates to an extruding, guiding and strengthening device of a vertical extruding machine of a large-diameter and thick-wall stainless steel pipe, belonging to the technical field of metal extrusion. According to the extruding guiding and strengthening device, a high-temperature alloy extruding die seat guiding lining is fixedly connected with a die seat lengthening guiding and straightening sleeve by a transition connector to form an assembly. At the initial stage of hotly extruding a steel pipe, when the temperature of the steel pipe is 1000-1100 DEG C, extruding and ejecting force is used for guiding and straightening the extruded steel pipe in real time; the steel pipe is extruded while is guided and straightened; and the bending generated at the head of the steel pipe is effectively straightened. After the guiding and straightening device is additionally arranged, on the one hand, the bending phenomenon of the head of the steel pipe is controlled and the head of the steel pipe is effectively utilized, and the material utilization rate can be improved by 5%-10%; and on the other hand, the bending degree of the whole steel pipe is greatly reduced until the extrusion is finished in a whole extruding process, secondary heating and straightening does not need to be carried out, a subsequent straightening working procedure is simplified, the efficiency is improved and energy sources are saved.