Cognitive　radio　technology　is　a　new　communication　technology　to　cope　with　the　increasing　demand　and　inefficient　use　of　radio　spectrum.　This　paper　summarizes　the　historical　development　of　CR　technology,　from　its　initial　concept　to　the　present　research　status　and　shortcomings.　This　paper　mainly　introduces　spectrum　detection　and　allocation　technology　in　CR　network　and　some　applications　of　CR　technology　in　real　life.　This　paper　makes　up　for　the　lack　of　review　papers　on　the　development　and　application　of　the　latest　spectrum　technology　of　CR　in　recent　years.　In　terms　of　future　challenges,　this　paper　analyzes　the　environmental　and　ethical　issues　faced　by　this　technology　in　recent　years,　some　research　bottlenecks　in　6G　technology　and　some　breakthroughs　in　the　field　of　satellite　communication.　©　2024　SPIE.