We use single- and double-lens systems to develop the short magnetic focusing image converter tubes respectively, and simulate the electronic motion imaging to study the imaging distortion by the Lorentz 3D-EM software. When the imaging ratio is 1∶1 and the cathode voltage is -3 kV, the spatial resolutions of the single- and double-lens systems are 17.07 lp/mm and 24.49 lp/mm respectively; the imaging distortion rates of single- and double-lens systems are 1.43% and 0.98% at 6 mm off axis respectively; the imaging distortion rates of single- and double-lens systems are 7.5% and 2.5% at 12 mm off axis respectively. Experimental results show that the imaging distortion rates of single- and double-lens systems are 2.4% and 0.9% at 6 mm off axis respectively; the imaging distortion rates of single- and double-lens systems are 8.5% and 3.2% at 12 mm off axis respectively. It is concluded that the double-magnetic-lens imaging system can reduce the imaging distortion and improve the spatial resolution.