The present disclosure is applied to the field of communications, and provides a channel assignment, acquisition method and system, the assignment method including: selecting at least one idle channel from idle channels of a multi-channel sharing system as a control channel; sending an idle signal to the control channel, the idle signal identifying that the control channel is a control channel for a customer premise equipment (CPE) to be positioned therein in a preset positioning manner; and upon receipt of a communication request from a CPE positioned to the control channel, assigning the control channel to the CPE. The present disclosure, by selecting one idle channel as a control channel, positioning a CPE to the control channel after the CPE scans the control channel, and conducting communication through the control channel, can not only achieve dynamic assignment of the channel, but also make the amount of computation of the dynamic assignment small and control complexity of the dynamic assignment lower.