Current analysis was an important research content for reducing power of cryocooler’s controller. Simulation was done among load current, H bridge current and power current refer to 42V bus power voltage. Then relationship among I<sub>L1</sub>, I<sub>C1</sub>, ρ and I<sub>M1</sub> was established. Simulation results indicate that I<sub>L1-max</sub>, I<sub>L1-ave</sub>, I<sub>L1-rms</sub>, I<sub>C1-min </sub>and <sub>IC1-ave</sub> were linearly increasing to ρ and I<sub>M1</sub>, especially I<sub>L1-rms</sub> ≈ 0.612ρ I<sub>M1-max </sub>. I<sub>C1-rms</sub> increase firstly then decrease with the increasing of ρ. I<sub>C1-rms </sub>reaches maximum when ρ=0.8, then I<sub>CL-rms</sub> =(12.32/R<sub>M1</sub> + 0.98) exp <sup>-((ρ-0.78)/0.57)<sup>2</sup></sup>. The results were useful for miniaturizing cryocooler’s controller.