The invention discloses an automatic harvesting device and method of cordyceps cicadae cultures. The automatic harvesting device comprises a longitudinal conveying assembly and a harvesting assembly,wherein the longitudinal conveying assembly is used for fixing and conveying the cordyceps cicadae cultures and comprises a longitudinal conveying platform and clamping devices, and the clamping devices are arranged at the upper end and the lower end of the longitudinal conveying platform and used for clamping the cordyceps cicadae cultures to synchronously move along with the longitudinal conveying platform; and the harvesting assembly is used for cutting the cordyceps cicadae cultures into sporocarp and mycoplasm and comprises a harvesting tool and a material collecting device, the longitudinal conveying platform moves opposite to the harvesting tool, the harvesting tool cuts the cordyceps cicadae cultures on the clamping devices to separate out the sporocarp, the material collecting device is arranged on the bottom of the harvesting tool and used for collecting the mycoplasm, and the clamping devices clamp the mycoplasm to continue to move along with the longitudinal conveying platform. By means of the automatic harvesting device and method of the cordyceps cicadae cultures, efficient cordyceps cicadae culture harvesting is achieved, the operation labor intensity of workers is low, the automatic harvesting device and method of the cordyceps cicadae cultures can be suitable for harvesting the cordyceps cicadae cultures in different specifications and thicknesses, and efficient scale cultivation of the cordyceps cicadae is achieved.