The invention relates to a pressure sensitive array calibration device for detecting or calibrating a mechanical instrument and a method thereof. The device comprises a pressure sensitive array calibration supporting plate, a pressure sensitive array calibration pore plate, a weight loading plate and a signal conditioning acquisition circuit. The method comprises the following steps of: placing a pressure sensitive array to be calibrated between the pressure sensitive array calibration supporting plate and the pressure sensitive array calibration pore plate; and placing the weight loading plate in a through hole array on the pressure sensitive array calibration pore plate, loading weights on a top plate of the weight loading plate from zero to full scale step by step, and recording a measurement result and carrying out signal processing by the signal conditioning acquisition circuit so as to obtain a calibration result. According to the invention, the pressure sensitive arrays to be calibrated, which have different distribution densities, can be rapidly calibrated in the field; the design of array through holes needs equipment a little; a weight loading mode is directly adopted and third-party measurement equipment is not adopted to calibrate, so that the calibration accuracy is improved; and the pressure sensitive array calibration device is convenient to use.