The invention relates to a typesetting file preprocessing method, belonging to the filed of processing computer information. There is no effective typesetting file preprocessing method in the existing techniques. And as typesetting a file, the existing typesetting software will cause multiple errors, such as incorrect previewing picture and wrong typeset result, if there is any error in the source file, and will cause the file produced by typesetting relative big, affecting the efficiency, if the source file is not compressed. The method of the invention firstly preprocesses a file to be put in to generate a standard compressed EPS file with previewing picture as typesetting by the existing typesetting software, and then using the EPS file to typeset. The method ensures the correct typeset result and the result file is relative small so as to be easy to store and transmit.