Kang Yu medical blood cell analyzer detection principle for the Coulter principle, is in the counting tube inside and outside each placed on a platinum electrode, the two electrodes between the application of a constant current, the test will be tested first with a clean electrolyte dilution of blood, so that the blood cells in the electrolyte to become a free bulk state, and then in the upper end of the counting tube to apply a negative pressure, the use of blood cells through the counting tube jewel holes in the electrical resistance change and the electrical pulse, the number of pulses on behalf of the counting tube. Then negative pressure is applied to the upper end of the counting tube, using the change in resistance of the blood cells when they pass through the jeweled holes of the counting tube to obtain electrical pulses, and the number of pulses represents the number of blood cells, thus achieving the purpose of counting.