A pressure measuring method, applied to a pressure measuring apparatus, comprising: measuring a first pressure sensing value when the pressure measuring apparatus operates at a first scan frequency and receives a first pressure; and measuring a second pressure sensing value when the pressure measuring apparatus operates a second scan frequency and receives the first pressure. The first pressure sensing value and the second pressure sensing value are different, and a change between the first pressure sensing value and the second pressure sensing value is according to a change between the first scan frequency and the second scan frequency. The first scan frequency and the second scan frequency are different. The pressure measuring method can further comprise a calibrating mechanism to compensate the sensed pressure. By this way, the pressure sensing value can be calibrated, to solve the issue that the pressure sensing values are affected by scan frequencies.