DICOM standard is an indispensable component of PACS, but due to non-DICOM images can be fast loaded and portable with compression, many non-DICOM medical imaging equipments are still widely used in the hospital system, which has led to existence of many non-DICOM medical images. However, the non-DICOM images are unsuitable for doctors to diagnose and study. In this paper, a low-load architecture is designed to communicate and archieve medical images by lowering the DICOM gateway based on the automatic switch between non-DICOM and DICOM formats. Analysis shows, compared with the traditional picture archiving and transmission systems, this system has made remarkable improvement and development on stability, compatibility, automation, scalability and practicability.