The invention relates to a method, a device and a system for realizing database multipath access. The method can comprise the following steps that: a management server transmits an instance creating notification to a database server in a cloud service environment network after an instance application request is received; the database server allocates database data storage space and creates a database instance with a first network address and a first port; a network address conversion server of a first cloud network creates a second network address and a second port, and maps the second network address and the second port to the first network address and the first port in order to form a first access path; and a network address conversion server of a second cloud network creates a third network address and a third port, and maps the third network address and the third port to the first network address and the first port in order to form a second access path. Through adoption of the system, a plurality of paths for accessing the same database can be created, so that mutual access to databases between different networks is realized.