A high-performance in-situ TiB2 particle reinforced 7050 Al matrix composite (in-situ TiB2/7050 composite) was successfully fabricated via additive friction stir deposition (AFSD). Microstructure and mechanical properties of both as-received and as-deposited materials were thoroughly examined. Results evidence that AFSD process can homogenize TiB2 particles and refine the microstructure of in-situ TiB2/7050 composite, thereby improving the mechanical properties. The average grain size and aspect ratio of the as-deposited in-situ TiB2/7050 composite were reduced to 2.17 μm and 1.78, respectively. After T6 heat treatment, the ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) of the as-deposited material were 653 MPa, 576 MPa, and 11.6 %, respectively. In comparison to the as-received material, the UTS and YS increased by 112.7 % and 96.6 %, respectively, and the EL remained largely unchanged.