The invention provides a method and a system for realizing private conversation in conversation process, wherein the method comprises the steps as follows: detecting current working state of a terminal device; transmitting a user prompt message and displaying the user prompt message when the terminal device is in conversation process so as to prompt a user to perform private setting for current conversation; receiving setting information inputted by the user; and performing corresponding storage for the conversation record of the current conversation according to the setting information. The method and the system of the invention can be used for setting the conversation in the conversation process as the private conversation and automatically storing in a private space so as to realize a private communication between terminal conversations to protect privacy security of the end user.