Terahertz (THz) technology enables multi-Tbps satellite communications, but conventional semiconductor detectors suffer from fundamental performance degradation above 1 THz due to the Drude limit of free electrons. Here, we theoretically demonstrate that charge density wave (CDW) materials offer a paradigm-shifting solution via their collective electronic response. We show that a static bias electric field can continuously tune the THz resonant absorption frequency of CDW states from 0 to cutoff frequency, and enhance the nonlinear rectification current by more than one order of magnitude. This unprecedented electric-field tunability makes CDW materials ideal candidates for next-generation ultrafast THz detectors working at room-temperature.