The invention provides a fully-automatic plant seedling digging, sealing and covering device. Earth covering traveling wheels of two sides of a mounting frame are connected through a transmission shaft, a tractor frame is arranged on the outer side of each earth covering traveling wheel, the transmission shaft is connected with the mounting frame through a bearing block, at least one soil storagecabin is arranged on the inner side of each soil storage cabin, an outlet end of the soil storage cabin of the uppermost portion of each soil storage cabin directly faces the inlet end of a soil conveying pipe, a driving chain wheel is arranged on one side of the bearing block and fixedly connected with the transmission shaft, and the transmission shaft drives a cutting drum of a cutting device tovertically move through chain transmission. According to the device, a thin film can be discontinuously cut by the cutting drum of the cutting device, so that seedlings are completely exposed, the damage rate of the thin film is reduced, soil conveyed by the soil conveying pipe covers roots of the seedlings when the film is damaged, general daily manual operating quality is about 5 hectares, thedaily operating quality of the device is about 15 hectares, operating efficiency is greatly improved, time is saved, and operating cost is reduced.