The invention relates to a connecting system of the needle of safety syringe (100) consisting of a frontal process (11) of plunger (1) and a shaped bore (121) in the needle hub (12). The frontal process (11) is made on the front part of the plunger (1) and aligned along, or tilted against the longitudinal axis of the syringe, and against the front process (11) a shaped bore (121) with tapered inlet is made in the needle hub (12). The principle is that the frontal process (11) of the plunger (1) is made as a radially springing fork with front conical extension (111) where the base (1110) of the cone of this conical extension (111) is planar or shows a deflection near its circumference, namely from the plane perpendicular to the longitudinal axis of the respective cone, with a size up to 5 angular degrees, and concurrently, the shaped bore (121) in the needle hub (12) has a bottom guiding and entry area (122) which is conical, and inside back-blocking area (123), which is planar or shows a deflection near its central bore from the plane perpendicular to the longitudinal axis of the respective hub, with a size up to 5 angular degrees, while the cone surface area of the conical extension (111) of the front process (11) of plunger (1) is made as a two-stage at least, with different top angles or continuously variable top angle.La présente invention concerne un système de raccordement de laiguille dune seringue de sécurité (100) consistant en un processus avant (11) de plongeur (1) et un canal façonné (121) dans lembase de laiguille (12). Le processus avant (11) est formé sur la partie avant du plongeur (1) et aligné sur, ou incliné contre, laxe longitudinal de la seringue, et un canal façonné (121) avec un orifice dentrée se réduisant progressivement est formé dans lembase daiguille (12) contre le processus avant (11). Le principe est que le processus avant (11) du plongeur (1) est formé sous la forme dune fourche à détente radiale avec une extension avant conique (111)