An optimized occlusion detection method for true orthophoto make is proposed in this paper, aimed at solving the occlusion and shadow problems caused by rectification using digital surface model (DSM). This method draws lessons from sweep way of angle-based detection method and idea of radial tracing detection method. It adds three judge rules to the occlusion detection process to increase its executing efficiency. Using neighbor image's best corresponding pixels can compensate the occlusion area.