For enhancing stability of the Nd:GdVO4 linear cavity blue laser, the thermal lens effect of Nd:GdVO4(gadolinium vanadate) crystal was analyzed with diode end-pumped. It focused on the relationship between the output power and thermal lens focal length of 447 nm blue laser. By improving the method of dynamic stable resonators and using MATLAB and the Matrix Laser, the parameters were optimized such as length of the resonant cavity, the radius of curvature of the input/output mirror and location of the various components in the cavity. The result of the imitation and experiment shows that the cavity has a good dynamic thermal stability.