ZnAl particle-reinforced Fe-based amorphous composites were prepared using pressureless sintering. The structure, thermal stability, and thermal conductivity of the composites were analyzed using X-ray diffractometer, scanning electron microscope, differential thermal analyzer, and laser flash thermal conductivity tester. The results showed that dense ZnAl/Fe-based amorphous composites could be obtained by pressureless sintering in the supercooled liquid region; the introduction of ZnAl did not affect the nature of the Fe-based amorphous matrix; no interfacial reaction phase was generated during the sintering process; the thermal stability of the composite was slightly reduced, but the reduction was not significant; in the range of 298 ~ 423 K, the composite had a lower thermal conductivity coefficient than the Fe-based amorphous alloy, and its thermal diffusivity did not change significantly with increasing temperature, indicating good insulation performance.