An intracavity frequency doubling acousto-optically Q-switched Neodymium-doped Yttrium Orthvanadate (Nd:YVO₄) 457 nm blue laser by employing a three-mirror folded cavity was demonstrated. With the incident pump power of 40.4 W, the maximum average output power of 439 mW 457 nm laser, and the minimum pulse duration of 86.14 ns and the maximum peak power of 510 W were achieved at 10 kHz. The M² factors are 1.23 and 1.61 in X and Y directions, respectively. The power stability in two hours is better than 2%.