Taking LYTRO camera as an example, a fast multi-target ranging method based on microlens array (MLA) light field camera is proposed. The process of the method is divided into three parts. In the first part, the paper acquire the re-focusing sequence images of the data by calculating the point spread function, restoring the color of the original data and conducting the super resolution. Then the pretreatment process of the target is completed. In the second part, a direct ranging method is proposed by using the principle of triangle and patch method. In the third part, the existing relative ranging method is optimized by super-resolution processing, which greatly improves the accuracy of the original algorithm. At the same time, the correctness of the algorithm is verified by the improved Laplace operator. Finally, a fast multi-target ranging algorithm for MLA light field camera is obtained by combining the two algorithms. Experiments results show that, for small number of objects to be measured, the direct ranging method is with high accuracy and fast speed, and for large number of objects to be measured, the combination of direct ranging method and relative ranging method can not only ensure the accuracy, but also greatly improve the timeliness. The proposed method can provide important data reference and more accurate evaluation basis for depth acquisition and three-dimensional reconstruction of light field camera.