The utility model discloses a pressure relief preventing device of an emergency shut-off valve and an emergency shut-off valve assembly, and belongs to the field of valves. The pressure relief preventing device of the emergency shut-off valve comprises a female part, an elastic part, a blocking part and a male part, the female part and the male part are each provided with a hollow tubular structure, and the first end of the female part is fixedly connected with the first end of the male part; the elastic piece and the blocking piece are arranged in the tubular structure of the female piece, the first end of the elastic piece makes contact with the blocking piece, and the elastic force direction of the elastic piece to the blocking piece is the direction pointing to the male piece from thefemale piece. When the fluid pressure borne by the blocking piece is balanced, the blocking piece makes contact with the pipe opening of the first end of the male piece under the elastic force effectof the elastic piece, and a sealing structure is formed. By adopting the emergency shut-off valve, the problem of abnormal shut-off of the emergency shut-off valve caused by air source failure or airleakage of the air guide pipe can be effectively solved.