A quick connector having an anti-disengagement structure includes a first body, a second body and a locking member. The locking member is connected to one end of the first body and stopped by an oil seal. The second body is connected to the first body and the locking member is fitted on the second body. A locking block of the locking member is engaged in a locking recess of the second body to complete the assembly of the first body, the second body and the locking member. Particularly, the locking recess has an anti-disengagement design to prevent any unexpected disengagement and to ensure the connection of the connector.