With the aim to realize Quantum Efficiency(QE) measurement of photon detectors based on Spontaneous Parametric Down-conversion(SPDC),two type of coincidence count systems were set up,the correction factors of coincidence count were analyzed and the real experimental methods of correction factors were given. Firstly, the principle of SPDC and the technique using SPDC to calibrate the QE of photo detectors was introduced. Then the design of two type of coincidence count systems, gated dual-photon counter coincidence count system and TAC/MCA coincidence count system,were introduced. Finally, the main correction factors, accidental coincidence, missing coincidence, dead time of counters and detectors were analyzed, and the calculation and test methods were also given. Experimental results show that the deviation between this two type of coincidence setups is less than 0.4% after correction, which indicates that the two setups can satisfy the requirement of QE measurement.