Abstract: Fe nanoparticles were synthesized by a new method of pulse laser gas phase evaporation-liquid phase collection. The morphology, structure, magnetic properties and synthesis mechanism were studied by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and vibration magnetometer. The results showed that using 45^# steel as the target, 20% ethylene glycol+80% ethanol as the liquid collection system, and N2 as the carrier gas, Fe nanoparticles are successfully prepared under the conditions of the laser power density 42 J/mm², pulse width 3 ms, frequency 10 Hz, and the N2 flow 0.5 L/min. The particles are spherical and show a trend of chain connectivity, the main size of the Fe particles is 20~30 nm; the coercivity of iron nanoparticles is 523 Oe, the saturation magnetization is 45 emu/g. The plasma with Fe composition was generated from 45^# steel target by pulsed laser ablation, after homogeneous nucleation and growing of crystal nucleus in the gas phase, Fe crystal nucleus grew up to nano-size Fe particles when they were carried by N2 into the liquid phase. Ethylene glycol in the liquid has played a role in the dispersion of Fe nanoparticles in situ.