The invention provides a continuous blood pressure measuring device. The method for measuring blood pressure by the device comprises the following steps of: selecting features used for blood pressure equation estimation from a large number of extracted features by feature selection, sending the selected features into a decision system, and determining equations used for estimating the blood pressure from blood pressure simultaneous equations; selecting the features used for estimating coefficients of the blood pressure equations from the features which are extracted from feature extraction by feature selection, and estimating the coefficients of the blood pressure equations by statistical estimation, digital computation and other methods; and finally selecting the features used for estimating the blood pressure from the features which are extracted from the feature extraction by feature selection, and substituting the selected features into the blood pressure equations to estimate blood pressure. By a multi-feature-based pulse wave velocity method and a blood pressure simultaneous equation establishment method, the blood pressure estimation is performed by artificial intelligence, pattern recognition and other ways to ensure that not only the measurement accuracy of the blood pressure estimation is improved but also a complicated parameter calibrating process is avoided.