1. A chatting system for a virtual pet, comprising: a pet client, configured to receive a natural language sentence of a pet master, and send the natural language sentence to a virtual pet server; the virtual pet server, configured to forward the natural language sentence to a questioning and answering server, and return a natural language response to the pet client; the questioning and answering server, configured to perform processing of natural language understanding on the natural language sentence; obtain language characteristics of the pet master; generate the natural language response according to a natural language understanding result and the language characteristics of the pet master; and return the natural language response to the virtual pet server.