Disclosed in the present invention are an electrocardiographic signal-based airbag-free blood pressure measurement method and system. Said method comprises acquiring an electrocardiographic signal, and acquiring a pRRx sequence corresponding to the electrocardiographic signal, performing linear analysis and/or non-linear analysis on the pRRx sequence to obtain a corresponding characteristic index, performing machine learning using the characteristic index and the corresponding blood pressure value, which are obtained by means of calculation, as an input and a label, and performing training to obtain a model function of the correlation between the characteristic index of the electrocardiographic signal and the blood pressure value; and when the blood pressure value at a certain time point is to be detected, acquiring an electrocardiographic signal prior to the time point, performing calculation and obtaining, according to the characteristic index of the electrocardiographic signal, the blood pressure value at the time point by means of the model function. Compared with the prior art, the present invention acquires an electrocardiographic signal as a source signal in a non-invasive and airbag-free manner, having a low cost, being safe and effective, facilitating continuous measurement operations, and providing a better user experience; in addition, this method involves a small amount of calculation in the blood pressure measurement process, enabling low algorithm complexity, and high efficiency.