Walnut picking machine for orchard

The invention provides an orchard walnut picking machine, and belongs to the technical field of walnut picking and screening. In order to solve the problem that walnuts and impurities cannot be separated after the walnuts are picked by a machine in the prior art, the picking machine is provided with a gathering mechanism, a conveying mechanism, a guide mechanism, a separation mechanism, a sweeping mechanism and a collecting mechanism, and the walnuts mixed with the impurities at the front end of a vehicle body are gathered by the gathering mechanism, then stacked upwards and lifted to the conveying mechanism; the walnuts are conveyed to the top through the conveying mechanism from bottom to top and then fall into the separating mechanism through the guiding mechanism, the walnuts are thrown out of the outer side of the screening disc to enter the large collecting frame after being subjected to rotating centrifugation of the separating mechanism, impurities fall into the large collecting frame from a center th