The invention discloses a seedling tray conveying device used for a vegetable transplanting machine and relates to the field of transplanting machines. The seedling tray conveying device used for thevegetable transplanting machine comprises a base, a lifting conveying mechanism and a tooth profile conveying mechanism, wherein the lifting conveying mechanism and the tooth profile conveying mechanism are arranged on the base side by side; a seedling tray sliding groove is obliquely formed between the lifting conveying mechanism and the tooth profile conveying mechanism; one end of the seedlingtray sliding groove is fixedly connected with the upper portion of the lifting conveying mechanism; and the other end of the seedling tray sliding groove is connected with the tooth profile conveyingmechanism. The seedling tray conveying device used for the vegetable transplanting machine has the beneficial effects that the seedling tray conveying device is applicable to common full-automatic vegetable transplanting machines, is high in seedling tray collecting and taking accuracy and high in efficiency, and can achieve mechanical automation very easily, and after electrical and hydraulic joint control is adopted, not only can the automatic control process in higher degree be achieved, but also remote control can be achieved.