Abstract: This paper introduces the structural design of a spiral 1/10 micrometer. The differential tube of 1/10 micrometer adopts double thread, the spiral direction of the two threads is the same, and the pitch is different.The V-groove and V-block are precisely positioned to increase the range. The minimum measurement scale can be up to 0.001 mm and The reading accuracy is up to 0.0001 mm. The 1/10 micrometer adopts pure mechanical structure, the structure principle is simple, and the manufacturing and installation are convenient.