The invention discloses a method for digitally adjusting inclination of micro-lens arrays in light-field cameras. The method includes imaging uniform white surface light sources by the aid of the light-field cameras to generate white images; processing light spots of different regions in the white images by the aid of connected region searching and metering processes in image morphology and computing the average sizes of the light spots; judging whether the micro-lens arrays are inclined relative to target surfaces of imaging chips or not according to the size relations among the light spots of the different regions. The method has the advantages that a digital index can be provided for inclination errors of the micro-lens arrays, then the micro-lens arrays can be adjusted according to the index, accordingly, the inclination errors of the micro-lens arrays in the light-field cameras can be reduced and even can be eliminated, the light-field camera assembly difficulty can be lowered, and the imaging quality of the light-field cameras can be improved.