Spectrum sensing is a key function in cognitive radio network (CRN) that can identify the free spectrum to improve spectrum utilization and avoid harmful interference to licensed users. However, due to various challenges caused by multipath fading, shadowing, receiver uncertainty, etc., the detection of licensed users fails. Cooperative Spectrum Sensing (CSS) technology minimizes the impact of these issues and improves detection performance by exploiting spatial diversity. This paper first introduces the brief history of cognitive wireless networks and spectrum sensing technology, then conducts a brief study on cooperative spectrum sensing, discusses different types of cooperative spectrum sensing technology, cooperative models, feature comparison, and analyzes some related earlier works with involved challenges.