The invention discloses an ultrasonic and infrared combined positioning device, which comprises a touch screen and a touch pen, wherein a microprocessor, an infrared transmitting tube and an infrared receiving tube are arranged on the touch screen; and the positioning device also comprises an ultrasonic receiver and an ultrasonic transmitter, wherein the ultrasonic receiver is arranged on the touch screen, and the ultrasonic transmitter are arranged on the touch pen. The invention also discloses an ultrasonic and infrared combined positioning method, which comprises the following steps of: S1, determining the distance between a touch point and the ultrasonic receiver and judging whether the number of the touch point is only one by the ultrasonic receiver, and if so, entering the S2; otherwise, jumping to the S3; S2, detecting the Y-axis coordinate of a positioning point, and jumping to the S4; S3, detecting the Y-axis coordinates Y1,..., Yn of the touch points, and determining a positioning point; and S4, solving the X-axis coordinate of the positioning point, and returning to the S1. The positioning device has the advantages of accurate positioning, simple structure, low cost andthe like.