The invention discloses a pressure measurement system and a wiring method thereof, wherein the pressure measurement system is capable of acquiring and displaying measured pressure values in a test IMP (Interface Message Processor) data acquisition system and an in-situ DCS (Data Communication System) simultaneously. The system comprises the test IMP data acquisition system, a test pressure transmitter and an in-situ DCS measurement display system, wherein the positive pole of the DCS measurement display system is connected to the positive pole of the test pressure transmitter, the negative pole of the test pressure transmitter is connected to the negative pole of the test IMP data acquisition system, the direct-current 24V power-up wiring part of the test IMP data acquisition system is in short circuit, the positive pole of the test IMP data acquisition system is connected with the negative pole of the DCS measurement display system, and the test IMP data acquisition system and the DCS measurement display system are connected with each other in series. By virtue of reasonable design of the wiring mode, internal structures and wiring modes of the test IMP data acquisition system and the DCS measurement system do not need to be changed, so that the precision and stability of the measurement system can be kept unchanged, and workload in site can be greatly reduced.