Abstract: The present invention discloses a lysin that is capable of killing Staphylococcus and the use thereof, belonging to the field of biological agents. The present invention discloses the amino acid sequence and the encoding gene sequence of the lysin. This lysin keeps active in a wide range of pH. It has lytic activity against Staphylococcus in pH 4-11. The recombinant protease constructed by the encoding gene can be solubly expressed in E. coli strain BL21 (DE3). The lysin can be used to effectively kill multiple species Staphylococcus in vitro, including methicillin sensitive Staphylococcus aureus (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) isolated in clinics. This lysin can be used as an antibiotic for the treatment of staphylococcal infections in vivo. This lysin is also able to rapidly lyse staphylococcal cell wall; as a result, intracellular substances such as ATP and DNA are released. Those released substances can be used to detect the type of Staphylococcus.