The invention provides a semi-dull high-strength low-elongation viscose fiber and a preparation method thereof. The viscose fiber is obtained by sequentially performing soaking, grinding, squeezing crushing, kneading, polymerization reduction, yellowing, dissolving, filtering, defoaming, curing, spinning drawing and after-treatment on a pulp raw material, and has the following indexes that the dry fracture strength is more than or equal to 3.10cN/dtex, the wet fracture strength is more than or equal to 1.60cN/dtex, the strength needed for generating 5% of the elongation in a wet state is more than or equal to 0.55cN/dtex, and the dry elongation at break is 11.0-19.0%. The high-strength low-elongation viscose fiber is a novel fiber variety realized by virtue of technical innovation, and has an index system which is different from that of ordinary viscose fibers and Modal fibers, and a product of the fiber shows the fiber characteristics of high strength and low elongation of the Modal fibers, and also shows skin affinity stronger than that of cotton fibers, so that the semi-dull high-strength low-elongation viscose fiber can effectively replace the existing differentiation viscose fiber, and the development and the industrial upgrading of downstream novel textiles are promoted while the processability of the downstream process of the viscose fiber is improved.