An extrusion molding die is provided which produces a tube that contains aportion inwhich the cross-sectional area ratio of an inner layer and outer layer inaxial cross-sectioncontinuously varies, wherein said cross-sectional area ratio can be changed ina short time. Theextrusion molding die 50 moves a second inner layer mandrel 54 in the axialdirection andchanges the flow passage volume of an inner layer resin flow passage 62a inaccordance withchanges in supply quantity of an inner layer forming resin.