Central venous pressure monitoring method and central venous pressure measuring instrument

The invention provides a central venous pressure monitoring method and a central venous pressure measuring instrument. The method is applied to a central venous pressure measuring instrument comprising a central venous pressure sensor and a display screen, and comprises the steps that a target spectral signal and a standard spectral signal are obtained, and the target spectral signal is obtained by measuring the preset position of the neck of a measured user through the central venous pressure sensor; the standard spectral signal is a theoretical normal spectral signal of a measured user; calculating the similarity between the target spectral signal and the standard spectral signal; when the similarity is lower than a preset similarity, determining that the target spectral signal is invalid, and outputting a first prompt signal which is used for prompting re-measurement of the central venous pressure; and when the similarity is greater than or equal to a preset similarity, determining that the target spectral