The invention provides a blood pressure measuring instrument. The blood pressure measuring instrument comprises a pulse wave sensor, a state sensor and a host machine. The pulse wave sensor is used for sensing pulse waves of a detected object and outputting pulse wave signals. The state sensor is used for sensing the state of the detected object and outputting state information. The host machine comprises a signal processing circuit. The signal processing circuit is connected with the pulse wave sensor and the state sensor respectively and is used for receiving the pulse wave signals output by the pulse wave sensor and the state information output by the state sensor, calculating a blood pressure value according to the pulse wave signals and carrying out monitoring and processing on blood pressure according to the state information of the detected object. The blood pressure measuring instrument can be used for obtaining the blood pressure value, sensing the state of the detected object through the state sensor, outputting the corresponding state information and carrying out monitoring and processing on the blood pressure according to the state information of the detected object so that the more accurate and reliable blood pressure valve can be obtained.