The invention belongs to the technical field of radar detection equipment and relates to a processing device for a radar signal for detecting oil spill from a ship. A vertical polarization antenna is connected with a duplexer through a signal wire; a first transceiver comprises a first magnetron and a first receiver; the first magnetron is connected with a first input end of the duplexer; the first receiver is connected with a first output end of the duplexer; the first receiver is further connected with a first signal distributor; the first signal distributor is connected with a ship traffic management radar processor; a second transceiver comprises a second magnetron and a second receiver; the second magnetron is connected with a second input end of the duplexer; the second receiver is connected with a second output end of the duplexer; the second receiver is further connected with a second signal distributor; the second signal distributor is connected with an oil spill radar processor. The processing device can be used for monitoring the ship and the oil spill phenomenon, detecting the oil spill phenomenon in time, immediately sending an early warning signal and saving oil spill rescue time.