In order to study the transportation and conversion of the electromagnetic energy from the pulsed power driver to Z-pinch load, a circuit model for the driver is analyzed, and coupled with magneto-hydrodynamics model for the load plasma. Our simulation results are compared with those obtained from circuit software and experimental results based on the “Qiangguang-I” facility. The simulated voltage and current waveform coincide well with the experimental results. Results show that the pulse width decreases and the peak increases as the pulse transmits from the storage capacitors to the pulse transmission line. When the storage capacitors are initially charged at 35 kV, the peak of electric powers at the transfer capacitor, the pulse forming line and the pulse output line are 0.23, 0.80 and 1.46 TW, respectively, and their rise-times (10%-90%) are 550, 160 and 45 ns, respectively. The load current is 1.5 MA and the X-ray radiation power is 0.58 TW.