The invention provides a portable drawing table with an adjustable angle for a building. A portable auxiliary device which has the adjustable angle and can be stored into a small cuboid is supplied for the existing design drawing process, so that the working efficiency is improved, the working environment is improved, and space waste is lowered; the table comprises two supporting bases of the consistent specification, a stretchable base connecting rod is arranged between the two supporting bases, the supporting bases are connected with a drawing board supporting arm through a detachable drawing board fixator, an inclined strut is arranged between the supporting base and the drawing board supporting arm, and a drawing board is arranged on the drawing board supporting arm; due to the simpledesign, the using requirement for various drawing designs can be met, meanwhile, the structure is reliable and orderly, the drawing table is suitable fro various different drawing board sizes, and theusing occasions are expanded; by arranging a drawing board and a backup drawing board, two drawing makers can draw at the same time.