The invention relates to a small three-dimensional ultrasonic transmitter with ultrasonic and infrared emission functions, and belongs to a three-dimensional ultrasonic transmitter.The small three-dimensional ultrasonic transmitter with the ultrasonic and infrared emission functionscomprises a spherical skeleton, two cylindrical PVDF piezoelectric films, four infrared transmitting tubes, and a driving circuit;the two PVDF piezoelectric films are mounted in two grooves of the spherical skeleton correspondingly, the four infrared transmitting tubes are mounted in infrared mounting circular holesof the spherical skeleton correspondingly, and the driving circuit is mounted in a base of the spherical skeleton. The small three-dimensional ultrasonic transmitter with the ultrasonic and infraredemission functionshas the advantages that the structure is novel, the two cylindrical PVDF films and the four infrared transmitting tubes are mounted on the small spherical skeleton, the overall sizeis decreasedwhile the ultrasonic and infrared emission functions are realized, omni-directional emissions of the ultrasonic and the infrared emission are realized, the beam angle is large, and the small three-dimensional ultrasonic transmitter with the ultrasonic and infrared emission functions is used as a transmitter for a three-dimensional ultrasonic positioning system;and the number of receivers can be decrease due to the large beam angleof the ultrasonic and the infrared emission, and the cost and installation complexity are reduced.