A compact and stable 473 nm continuous all-solid-state blue laser is reported. Simulation analysis of the relationship between the LBO crystal length and the laser output efficiency is done. An optimal length of 10 mm type Ⅰ phase-matching LBO crystal is chosen. Under the pump power of 3 W, 210 mW of the blue laser at 473 nm is obtained. The optical-to-optical conversion efficiency is up to 7%. The fluctuation of laser output power is less than 3%.