Aiming at the problems of complex process, long processing cycle and low working efficiency existing in traditional artificial soil detection, a novel design method of pretreatment platform was proposed for detecting organic matter, which can accurately detect soil organic matter content by uniform and stable machine operation. Based on this method, a set of automatic pretreatment platform for soil organic matter detection was constructed. The platform was mainly composed of handling manipulator, temperature control digestion unit, nondestructive transfer unit and electrical control system. At the same time, the configuration software scheduling system was built to realize the collaborative work of each unit, and the automatic pretreatment of soil organic matter was achieved with the way of assembly line operation. Standard soil samples were selected to test the repeatability and suitability of the platform. The experimental results showed that the standard deviation of repeated tests was no more than 0.56g/kg, the relative standard deviation was no more than 2.30%, and the relative difference was no more than 2.21%. All the test results were within the error range required by the standard value, which met the index requirements of the Ministry of Agriculture and Rural Affairs of China for soil testing indicators. The automatic pretreatment platform proposed had high stability, which greatly improved the detection efficiency of soil organic matter detection without reducing the detection accuracy. The platform could replace the cumbersome process in traditional artificial soil detection, and it had a wide range of systemic applicability.