In the experiment of laser diode (LD) pumped intracavity frequency doubled Nd∶GdVO4/LBO deep blue 456 nm laser, in order to examine the effect of different neodymium concentrations in laser crystal on output power of frequency-doubled laser, two Nd∶GdVO4 crystals with the same size of 3 mm×3 mm×2 mm and different neodymium concentrations with Nd3+ ion atom fraction of 15% and 25% are compared. In the experiment , the same length of laser cavity of 20 mm and an Ⅰ-type phase-matched frequency-duobled medium of LBO for 914 nm with the length of 10 mm were used, a output power of 105 mW was obtained at incident pumped power of 2.85 W in the former crystal. In experiment, the laser crystal with higher dopant concentration obtained lower output power relative to that with lower dopant concentration. Through analyzing optimal crystal length in quasi-three-level laser system, the actual length of the 15% Nd3+ doped crystal is closer to the optimal length compared with the other crystal. Through analyzing the accurate cut-angle of frequency-doubled medium and temperature control of LBO, the difference of cut-angle for 912 nm and 914 nm may be compensated by controlling the temperature.