Abstract: An ice detector includes an icing assembly that includes a transparent icing rod with an illuminating element is disposed therein and having an ice accretion surface and a support structure. The icing rod has at least one visual sensor configured to obtain an image of the ice accretion surface; a controller electrically connected to the visual sensor and including an image contrast module configured to compare the obtained image with an initial image so as to judge whether ice is formed on the ice accretion surface of the icing rod. The icing assembly includes a refrigerating element respectively connected to the icing rod and the support structure. The refrigerating element may perform active refrigeration for the icing rod, reduce the surface temperature of the icing rod and facilitate the ice detector detecting ice accretion before ice is formed on a wing/nacelle.