Surveying and mapping ruler

The utility model relates to the technical field of surveying and mapping rulers, and discloses a surveying and mapping ruler which comprises a ruler body. A limiting groove is horizontally formed in the middle of the upper surface of the ruler body, a limiting block is slidably connected into the limiting groove, a scraping plate is horizontally arranged at the top end of the limiting block, cleaning cotton is detachably installed on the inner wall of the scraping plate, a sliding groove is formed in the middle of the upper surface of the limiting block, and a sliding block is slidably connected into the sliding groove. The limiting groove is in sliding connection with the limiting block, the scraping plate can be conveniently pushed to move on the ruler body, scale marks on the upper surface of the ruler body can be effectively cleaned through the cleaning cotton, coating is prevented from being attached to the ruler body, and the use precision is not affected; and the scraping plate can be pushed to be sto