The invention relates to an installation method for stern tube seal oil tubes and an installation method. The installation method comprises a plurality of through holes and a plurality of thread supports corresponding to the through holes, wherein the multiple through holes are formed in the surface of a stern tube equidistantly; one end of each thread support is provided with a fixing part havinga perforation used for fixing the oil tubes; the other end of each thread support is provided with an installation part capable of passing through the corresponding through hole; the exterior of eachfixing part is provided with a locknut in thread fit with the fixing part; and by improving the installation method for the stern tube seal oil tubes and the installation method, the problem that a worker cannot fix and install stern tube seal oil tubes for a small-pore diameter long stern tube is solved. After the installation method for the stern tube seal oil tubes is installed, any parts cannot be loosened or fall off, and a user does not need to worry about that the parts loosened and fall off to damage a ship stern shaft device during later use.