The invention relates to a decoding board of an ADS-B (automatic dependent surveillance broadcast) receiver. A digital logic circuit of the decoding board comprises an AD (analog-digital) conversion module and an FPGA (field programmable gate array) digital logic module; a baseband digital processing part of the FPGA digital logic module mainly comprises an input signal synchronization module, a preamble detection module, a code bit pickup and confidence analysis module, a CRC (cyclic redundancy check) error detection and correction module and a ping-pong FIFO (first in and first out) access data module. With the adoption of a dynamic detection threshold method, a problem of high possibility of data loss in a decoding process is solved; compared with an original method, the data size after decoding is increased; by improving a logic time sequence in a baseband data processing process, a problem of non-aligned transmission of decoding data by accident is solved, and a situation of transmission data dislocation is eliminated; after a test, the decoding board is stable in working and reliable in performance.