Abstract: A media session data transmission control method, a control relation negotiation method and a control device and a system thereof. The data transmission control method includes: the server obtains the media transmission right request of the sender (S601); the server distributes the first media transmission right for the sender based on the first media control strategy (S602); the control relation negotiation method includes: the server receives the media negotiation request from the caller, the media information to be negotiated is carried in the media negotiation request; the server establishes the corresponding media control relation for the caller based on the second media control strategy. Through the application of the media control strategy, the invention optimizes the existing media control process, provides more reasonable and efficient media control, the invention can be applied to multimedia and multiple party communication, and multimedia cluster communication widely.