In order to solve the problem that the success rate of pot seedling picking decreased due to the matrix loss in the process of the seedling detaching from the tray, orthogonal tests were carried out to study the influence of the cone angle of seedling tray(7°, 9°, 11°), compaction degree of matrix(1.0, 1.1, 1.2) and the moisture content of matrix(55%, 60%, 66%) on matrix loss rate of pot seedling during the process of pot seedling detaching from the movable tray. The test results showed that the average matrix loss rate was 3.09% in the process of pot seedling detaching from the movable tray. The influence of experimental factors on the matrix loss rate were the compaction degree of matrix, the cone angle of seedling tray and the moisture content of matrix from large to small. The optimal combination of experimental factors was as follow: the cone angle of seedling tray was 11°, the compaction degree of matrix was 1.2 and the moisture content of matrix was 66%, which achieved the lowest matrix loss rate of 2.62% in the process of pot seedling detaching from the movable tray.