Abstract: Equipment modification, technology upgrade of pilger mill trains and their modification which have great significance are discussed. The outputs of the 325mm and 210 mm pilger mill trains in Chengdu Seamless Steel tube Plant are increased by more than 30& of the design leve and more thant wenty sorts of special pipes and tunes such as oil casings(API), hydrauliclplant tubes, powerplant and boiler pipes,thip tubes and stainless steel pipes can be produced on the traius aftr techuological modification and modernization of the two trains. Some modified and modernized processes for trains are recommended on the basis of summing up of the above experiences.