The invention relates to a linear driver based on a piezoelectric fiber, and belongs to the field of micro/ nano precision drive. The linear driver is composed of a base (1), a pre-tightening force loading platform (2), a stator (3) and a mover (4), wherein the pre-tightening force loading platform (2) and the mover (4) are mounted on the base (1), and the stator (3) is mounted on the pre-tightening force loading platform (2) and is in elastic contact with the mover (4); the stator (3) comprises a compliant mechanism (3-1) and the piezoelectric fiber (3-2); by applying sawtooth wave driving electrical signals to the piezoelectric fiber (3-2), the piezoelectric fiber (3-2) is shortened slowly and elongated quickly, the stator (3) produces friction driving force, the friction driving force is transferred to the mover (4) via a semi-cylindrical driving head (3-1-4), and the mover (4) is driven to move based on the stick-slip principle. The linear driver has the advantages of simple structure, high precision and large travel, and can be applied in the fields of micro/ nano machining, precision optics, aerospace and the like.