The wavelength lateral distribution of high-power laser diode arrays (LDA) is tested. A V-type wavelength distribution is measured typically in the tested LDA. The measurements are carried under different driving currents,indicating that the thermal induced wavelength distribution is in protuberant shape and is opposite to the V-type. Based on the relation between stress and band-gap energy,it is show that the V-type stress distribution in LDA indicates the stress distribution in the laser chip. A linear stress distribution model is proposed to explain the experimental results. This work demonstrates that the measurement of lateral wavelength distribution can provide a useful method to detect bonding stress.