Traditional centralized electromagnetic spectrum monitoring platforms collect energy detection data from time, frequency and space dimensions. This method has high data redundancy. Combining the propagation loss characteristics and the signal direction finding (DF) data of each detection node, we focus on the signal source compressed parameter estimation. We propose a minimum average distance (MAD) method to improve the accuracy of collaborative detection in Cognitive Radio Network (CRN). The collaborative estimated data is stored in the blockchain structure to establish the distributed electromagnetic spectrum database (BC-DSDB). Based on the consensus mechanism Proof of High Confidence (POHC), the detection nodes maintain BC-DSDB independently. To regulate the rational utilization of electromagnetic spectrum resources, we propose the Spectrum Resource Currency (SRC) to evaluate the priority of the secondary user (SU) for dynamic spectrum access. When a spectrum collision event occurs between SUs, the spectrum time slice resources can be allocated according to the SRC. The experimental results show that BC-DSDB accurately describes the distribution of electromagnetic spectrum resources based on the propagation loss characteristics. At the same time, the redundancy of spectral data storage is reduced. SUs can quickly formulate dynamic spectrum access policies based on BC-DSDB and SRC in distributed cognitive radio networks.