The invention discloses a method for manufacturing an ultra-long titanium pipe or a titanium alloy pipe, which is sequentially carried out by the steps of the surface treatment of a titanium pipe billet or a titanium alloy pipe billet, making the titanium pipe billet or the titanium alloy pipe billet into a titanium crude pipe or a titanium alloy crude pipe, rolling the titanium crude pipe or thetitanium alloy crude pipe and straightening the rolled titanium pipe or titanium alloy pipe. The invention is characterized in that the straightening step of the rolled titanium pipe or titanium alloypipe comprises a pre-straightening step and a precise straightening step. The method of the invention of the manufacture of the ultra-long titanium pipe or the titanium alloy pipe has the advantagesof low linearity, comparative flatness, good quality, high yield, producing the ultra-long thin-wall titanium pipe or the titanium alloy pipe with the length of 12m to 16m, high yield of finished products, good quality and low rejects rate.