The invention provides a safe and practical obstacle avoidance device for a plant pruning knife rest. The safe and practical obstacle avoidance device comprises a rack, wherein a roller is arranged atthe lower end of the rack, a handle is arranged on one side of the upper end of the rack, a smashing device is arranged above the rack, a lifting table is arranged on one side of the smashing deviceand is located at the upper end of the rack, the upper end of the lifting table is connected with a fixing plate, a guide rail is arranged on the fixing plate, a sliding block is arranged on the guiderail, one end of the sliding block is connected with a telescopic rod, one end of the telescopic rod is connected with a motor, the output end of the motor is connected with a pruning device througha rotary telescopic rod, the guide rail is arranged on the fixing plate, the sliding block is arranged on the guide rail, one end of the sliding block is connected with the telescopic rod, one end ofthe telescopic rod is connected with the motor, the output end of the motor is connected with the pruning device through the rotary telescopic rod. The safe and practical obstacle avoidance device hasthe advantages of being simple in operation, good in pruning effect, capable of effectively preventing the knife rest from being abraded and saving energy and low in cost and being friendly to the environment.