The invention discloses an invoice identifying method based on plug-in, and an identifying and management system. The invoice identifying method includes the following steps: guiding a pre-established identifying plug-in to a dynamic link library, wherein the identifying plug-in is established on the basis of an identifying algorithm which corresponds to an invoice type; acquiring image information of a to-be-identified invoice and the type thereof; on the basis of the type of the to-be-identified invoice, invoking a corresponding identifying plug-in from the dynamic link library so as to identify the image information of the to-be-identified invoice and further acquire required invoice information. According to the invention, the invoice identifying method herein has the advantages that: 1. workers can input invoice information, submitting the invoice information to a back stage for an accounting worker to handle so as to reduce accounting worker's burden; and 2. when new type invoice appears, workers can dynamically add identifying algorithm for the type invoice to the system, such that a system can identify the new type invoice and the problem of identifying multiple types of invoices is resolved from an engineering aspect.