Anti-backflow and solidified-liquid plastic bag

The utility model provides an anti-backflow and solidified-liquid plastic bag, which comprises an outer bag and an inner bag, wherein the inner bag is arranged in the outer bag, both ends of the inner bag are open, one end of the outer bag is sealed, the other end of the outer bag is open or sealed, the whole edge at the opening part of the upper end of the inner bag is connected to the inner wall of the outer bag through annular sleeving, the lower end of the inner bag is provided with a plurality of welding spots, one lateral surface, at the position of the welding spots, of the inner bag and the other lateral surface of the inner bag are connected together through the welding spots, and a channel is formed between the two adjacent welding spots. According to the anti-backflow plastic bag provided by the utility model, no matter how the bag is placed, a liquid cannot backwards flow out of the plastic bag, so that the anti-backflow plastic bag is applicable to loading and storing a human-body liquid sample n