The work aims to explore a more efficient laser shock peening method, and improve fatigue life of TC17 titanium alloy sheet bars. Firstly, TC17 titanium alloy sheet bars were peened with four optical paths, then surface residual stress of the sheet bars was measured with LXRD-X-ray stress analyzer, and finally surface roughness test was performed to the sheet bars. New sheet bars were selected to perform stress distribution test and determine stress level of the TC17 titanium alloy sheet bars in first-order bending mode. Then, fatigue comparison test was performed to original sheet bars and shock peened ones at the stress level. A residual compressive stress layer took shape on the surface of the sheet bars. Provided with the same laser energy, residual stress of elliptic spot peened area wasabout 1.33 times that of rectangular spot peened area.Residual stress value in each point in the elliptic area differed slightly from each other. Surface roughness of peened area was 0.25～0.34 mm, and for unpeened area, 0.13～0.16 mm. In the fatigue test, the sheet bars not receiving laser impact peening fractured in 6～11 minutes. Among 4 sheet bars receiving laser impact peening, one did not fracture, and the other three fractured in 59, 381 and 709 min, respectively. Laser shock peening can enhance properties of materials, peening ofelliptic spot is superior tothat of square spot. Surface roughness of sheet bars increases by 1 times and fatigue life by 53 times after laser shock peening.