A pruning and fertilizing device of a green belt is used for pruning and fertilizing trees and comprises a cutting knife and a driving motor, wherein a collection opening is formed in the top of the cutting knife, branches and leaves pruned off are sucked by a draught fan into a smashing box for smashing, and the smashed branches and leaves mixed with nutrient solution can be used as a fertilizer of vegetations. The pruning and fertilizing device disclosed by the invention has a simple structure, can fertilize the vegetations when the branches and leaves are pruned and is suitable for industrial production.