The invention provides a trapezoidal belt forming machine which comprises a machine table, a counter, a stamping driving device, a stamping die installed on the machine table and an automatic cut-off device. The counter is installed on the machine table and is located between the stamping die and the automatic cut-off device. The stamping die comprises an upper die seat and a lower die seat. The stamping driving device drives the upper die seat to vertically move in the vertical direction. Raw materials can be stamped into a finished product piece of a trapezoidal belt through the upper die seat and the lower die seat, a guiding mechanism with guiding and buffering functions is arranged, and the machining precision of the trapezoidal belt is high. In addition, the distance between upper pressing plates or the distance between lower pressing plates can be properly adjusted according to different production requirements, universality is high, and the application range is wide. The counter is arranged on the machine table so that the length of the produced trapezoidal belt can be metered accurately, the automatic cut-off device is controlled to act by measuring the length of the trapezoidal belt through the counter, the trapezoidal belt can be accurately cut to be manufactured into a finished product, and the production efficiency is high.