The invention relates to a test unit for the erosion wear of diamond bit matrix material and a measuring method thereof. The test unit of the invention adopts a slurry closed loop system to jet slurry to two samples through double nozzles; and the unit adopts an in-situ three-electrode method, wherein the three electrodes arranged in a test chamber are respectively a working electrode, a reference electrode and a counter electrode, and all the three electrodes are connected with an electrochemical workstation controlled by PC. The test unit can perform test to simulate the erosion wear of diamond bit matrix material under actual working condition, and has stable performance and good repeatability. The invention also provides a measuring method for the erosion wear through applying the test unit, which can measure the electrochemical corrosion and pure mechanical washing of the matrix material, and mass loss generated by the mutual action thereof, the measuring method is simple, is easy to operate, can be applied to manufacturing industries such as diamond bit, petroleum drilling, composite material and the like, and can quantitatively evaluate various performances under the action of erosion wear.