The invention relates to a method for unfolding a character. The method comprises steps of: A1, acquiring the girth height and the inclined angle of the unfolded character; A2, making a corresponding character on a drawing tool and stretching the character to the girth height and forwardly rotating the character by 45 degrees; A3, making a rhombus with an included angle equal to the inclined angle on the drawing tool; A4, solving the lengths of the two diagonals of the rhombus and the length of a diagonal of a square with sides equal to the sides of the rhombus; A5, scaling the forwardly-rotated character by using a ratio of the longer diagonal length of the rhombus to the diagonal length of the square as a vertical scaling proportion and using a ratio of the shorter diagonal length of the rhombus to the diagonal length of the square as a horizontal scaling proportion; and A6, backwardly rotating the scaled character to a horizontal position so as to obtain a required unfolded character. The method reduces repeated correction of the character and reduces cost while improving the attractive appearance of a ship.