Before the operation. The signature on the operation safety checklist should be carried out before the operation to ensure that no safety accidents will occur during the operation. Signatories include patients or their guardians, surgeons and nurses. Before signing, the personnel of the three parties should confirm the information such as operation type, patient identity, surgeon, operation time, operation place and operation safety measures to ensure the safety during the operation. After the three parties sign, they have the responsibility to ensure that there will be no safety problems during the operation and ensure the safety of patients and medical staff.