The invention discloses novel temperature difference gradient type stem washing equipment and a stem washing method thereof and aims to provide the novel temperature difference gradient type stem washing equipment which is simple to operate and the stem washing method of the novel temperature difference gradient type stem washing equipment. The novel temperature difference gradient type stem washing equipment comprises a feeding conveying belt and at least two washing devices sequentially arranged at an output end of the feeding conveying belt; each washing device comprises a washing tank, an ultrasonic transducer mounted at the bottom of the washing tank, a circulating pipe with two ends communicated with the lower part of the washing tank, a circulating water pump mounted on the circulating pipe, a heat exchanger for heating a liquid in the washing tank as well as a discharging chain plate obliquely arranged in the washing tank; the output end of the feeding conveying belt is located at the upper end of the washing tank of the washing device adjacent to the back side of the feeding conveying belt, an output end of the discharging chain plate of each washing device is located at the upper end of the washing tank of the washing device adjacent to the back side of each washing device; a sewage outlet is arranged at the lower part of each washing tank and a solution supplementing port for supplementing a solution is formed in each washing tank.