The invention relates to an input method. Based on a directional dot-dash input technology, touch tracks of 52 directional dots and dashes are optimized and are respectively expressed by using 52 directional dot-dash symbols; 52 times of touch tracks are expressed by one or n logic input partitions based on a touch screen; meanwhile, the corresponding relation between each directional dot-dash symbol and various candidate set symbols (comprising character symbols and function symbols) is allowed to be freely set, the corresponding candidate set symbols can be outputted after specified directional dot-dash symbols are inputted. According to the input method disclosed by the invention, off-screen touch typing of touch screen input is realized for the first time, so that the accuracy of dot-dash input can be ensured and the diversification of input contents can be met; in addition, the input method has the advantages of simple algorithm, high response speed and low power consumption. Bases on a 10-key Pinyin input method disclosed by the invention, at most 520 symbols (including initial consonants and compound vowels of Pinyin, simplicity, Pinyin auxiliary codes, strokes of Chinese Characters, English letters, number, punctuation symbols and the like) can be simultaneously input without switching an interface; in addition, each kind of symbol at most slide for the length of two key positions.