The Nd：YVO₄ self-mode-locked picosecond laser was designed and studied, and also the best conditions of the mode-locked lasers were explored. The period-doubling self-mode-locked pulses and the quasi-periodic self-mode-locked pulses in the picosecond laser were observed and analyzed, and the output characteristics of the self-mode-locked laser with straight cavity in compact structure was studied and measured. The resonant cavity was concave flat chamber, under the condition of no other clamping device, the Nd：YVO₄ crystal as a laser gain medium and Kerr medium, and the high efficiency continuous mode-locked 1 064 nm laser pulses were outputted. The Nd：YVO₄ laser crystal is 16 mm from the input mirror, and the cavity length is 90 mm. The four kinds transmittance in 1 064 nm of output mirror are 10%, 20%, 30% and 50%, respectively, meanwhile the output characteristics of the laser were analyzed in comparison with different output mirrors. By optimizing the design, when the transmittance in 1 064 nm of output mirror is 10%, the output power of the laser is 2.76 W at 8 W incident pump power, and the slope efficiency is up to 43.2%, the repetition rate of mode-locked laser is 1.43 GHz, the laser achieves a high powered and stable continuous wavelength mode-locked.