The invention belongs to the field of bioengineering, and provides a bacteriophage capable of entering blood through oral administration and application of the bacteriophage. The bacteriophage monomer is a colibacteriophage; the Latin name is E.coli phage; the bacteriophage is named as Bp4; the bacteriophage has broad-spectrum sterilization capability on escherichia coli; the bacteriophage Bp4 is preserved in the general microbiology center of China Committee for Culture Collection of Microorganisms; the preservation date is 10th June, 2014; the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.9248. The bacteriophage has the strong cracking effect on the escherichia coli; bacteriophage sources are provided for industrial bacteriophage production, chicken colibacillosis prevention and control and environment sterilization, so that the severe escherichia coli viruses in a chicken farm are controlled. The bacteriophage can be used for industrial production, and the host bacterial escherichia coli specific amplification is realized. The bacteriophage can be used as a safe biological sterilization agent for environment sterilization. The bacteriophage can be used as biological antibiotic substitute to be applied to disease control in the chicken farm.