Blood vessel identifying method and device

The invention relates to method for recognizing human id by using bioassay technique. Operation steps are as following: (1) irradiating blood vessel part to be tested by using near infrared auxiliary light to collect texture image of blood vessel; (2) pretreatment of texture image including: carrying separation of background by using threshold tracking method of standard deviation to determine foreground and back ground, and removing noise through bilevel, then thinning operation; (3) distinguish out singular points, converting issue of authenticating vessel texture into the issue of dot mode matching; (4) converting point coordinates of singular point to polar coordinates, which is stored into database as template filed; (5) characteristic matching: locking reference position first, then carrying out comparison; in comparison template stored in database and user's PID number constitutes original template of characteristic data.