In this study, an efficient Fourier ptychographic microscopy method (FPM) based on an optimized pattern of light emitting diode (LED) angle illumination is proposed. First, a theoretical expandable spectrum range is obtained in the Fourier space based on the relationship among the LED, the aperture, and the sample. Second, image quality assessment methods are utilized to extract differential expressions to describe how an arbitrary LED affects the reconstruction effect. Third, the optimized angle illumination strategy is implemented based on the analysis of the differential expression. Then, a rhombus-based sampling approach is designed to accelerate the FPM process. Finally, the subjective and objective assessments are used to measure the validity of both simulation and actual experiments. Results indicate that our optimized method can effectively improve the efficiency by approximately 3.85 times compared with that of the traditional method.