The invention provides an ultrasonic radiation solvent extraction combination deep dehydration method and device applied to a biological solid matter. The method comprises the steps of ultrasonic radiation pretreatment, solvent extraction dehydration, solid-liquid separation and solvent recovery; water-containing biological solid matter is radiated by utilizing ultrasonic waves, so that the property of the biological solid matter is changed, cell disruption of the biological solid matter is performed, and more internal combined water of the biological solid matter is released; the biological solid matter radiated by the ultrasonic waves is in fully contact with a solvent of a low-boiling-point low-latent-heat matter, so that the solvent adsorbs and extracts water in the solid to remove the water from the solid; subsequently, the water-containing solvent is subjected to reduced-pressure evaporation or reduced-pressure vaporization in a separation device, so that the water and the solvent are separated, wherein the solvent is recycled after being compressed and condensed. The ultrasonic radiation solvent extraction combination deep dehydration method can remarkably reduce the water content of the biological solid matter.