To study the 3ω damage characteristics of DKDP crystals after 3ω conditioning, 3ω and 1ω conditioning at the same time, a dual-wavelength conditioning and damage test experimental system was established. The conditioning effects of 1ω energy density under dual wavelength irradiation were studied emphatically. The energy coupling mechanism in the conditioning process of dual-wavelength irradiation was analyzed. Research results show that the effect of dual-wavelength conditioning is significantly better than that of single wavelength. In the case of dual-wavelength simultaneous irradiation conditioning, the 1ω which is far below the threshold value of its own conditioning participates in the conditioning. Under the same conditioning strategy of 3ω energy density and energy gradient, there is an optimal value of 1ω energy density.