A weighted optical coupling array-based photoelectric arbitrary waveform generation scheme was proposed. In this scheme, different wavelength weighting and parallel coupling method were used to realize the DAC transform of signal optical domain. Through the spectral analysis of the signal, the time domain waveform was interfered by beat noise which was concentrated in the high frequency region. After wavelength presetting and filtering process, the high frequency noise could be effectively filtered out. However, some peak interference would appear at the time of signal alternation. When further filtering and smoothing process matching the bandwidth of the transform signal, the peak interference could be suppressed to a certain extent. Finally, the triangle wave, sawtooth wave, Gaussian pulse and square wave sequence were realized by the optical digital-to-analog conversion with signal rate of 10Gb/s and quantization accuracy of 5bits.