The invention relates to a diaphragm type pulsating blood pump driven by an ultrasonic motor, which belongs to the technical field of medical apparatuses. A fixed bottom plate is fixed on a base which is arranged on the output shaft side of an ultrasonic motor. A fixed outer barrel is connected with the fixed bottom plate. A sleeve barrel, an upper cover and the fixed outer barrel are connected into a whole. The upper and lower parts of a cam are fixed on a connecting lining barrel to form a barrel-shaped cam mechanism. The barrel-shaped cam mechanism and a driving disc are connected with theultrasonic motor by a tightening nut. One end of a push rod is embedded into a groove of the barrel-shaped cam mechanism, and the other end is connected with a push plate. A blood bag is arranged in an inner cavity which is formed between the push plate and the sleeve barrel. The other end of the blood bag is connected with the upper cover, and the blood bag is provided with a blood inlet and a blood outlet. Each blood opening is provided with a built-in check valve. The self structure of the ultrasonic motor is combined with the blood pump structure, the push rod and the push plate are arranged in the hollow barrel-shaped cam, and the blood bag is arranged in the hollow cavity of the sleeve barrel, so the structure of the pulsating type blood pump is compact, the volume is effectively decreased, the implantable capability is increased, and the application range for people is widened. The invention is free from the position limitation and has high driving efficiency and strong controllability.