With the rapid increase in the number of mobile users and the continuous update of wireless communication technology, data traffic has experienced a massive growth, and the demand for radio spectrum has also risen. The increasing demand for spectrum leads to the shortage of spectrum resources, and the current spectrum utilization method is relatively inefficient. In order to improve the utilization efficiency of spectrum resources and relieve the pressure of resource shortage, cognitive radio technology comes into being. This technology mainly improves spectrum utilization and communication efficiency through intelligent adaptive spectrum sensing and adjustment, among which spectrum sensing is its core content. This paper summarizes the research of spectrum sensing technology, mainly from the basic principles, models, current problems and future development direction are discussed.