Embodiments of this application provide a method for controlling quality of service (QoS) of sidelink communication performed at a core network entity. The method includes: obtaining QoS information configured by an application function (AF) entity for a sidelink; establishing a protocol data unit (PDU) session for the sidelink when determining, according to the QoS information, that the AF entity sets a per-flow QoS model for the sidelink, and generating a sidelink per-flow QoS parameter according to the QoS information; and configuring the sidelink per-flow QoS parameter on an access network entity and a terminal device, to control QoS of sidelink communication performed by the terminal device. In technical solutions of the embodiments of this application, a per-flow QoS mechanism can be implemented on a sidelink, thereby effectively improving effectiveness and reliability of communication on the sidelink and meeting service requirements of sidelink communication.