The utility model relates to the technical field of science education stationery products, in particular to an assistant exam special ruler used for filling an answer card. The special ruler is provided with various blank areas inosculated with the shape and the specification of the filling area of the answer card, and the blank area comprises a subject result area, an admission card number area, a subject area and an examination area, wherein, the blanks of the subject result area are provided with 5 rows, and the blank numbers of every row are five. The special ruler is not only convenient to fill the answer card rapidly and exactly for students but also convenient for filling-time conservation, and the students have enough time to answer questions, and the normal examination can be ensured; simultaneously, the examination area is also convenient for teachers to inspect test papers, and the inspection speed can be enhanced.