Three-way pipeline for monitoring concentration of substances in blood and monitoring system

The utility model discloses a three-way pipeline for monitoring the concentration of substances in blood and a monitoring system. The three-way pipeline comprises a three-way connecting piece, a probe tube, a body fluid tube and a detection tube, a Y-shaped tube is arranged in the three-way connecting piece, two branch tubes at the same end of the Y-shaped tube are respectively connected with the probe tube and the body fluid tube, and the other end of the Y-shaped tube is connected with the detection tube; and an irradiation tube is arranged at a preset position on the detection tube. The substance concentration monitoring system comprises a reagent booster, a micro permeation tube, a spectrum analyzer, a display, a laser transmitter, a shading box and the three-way pipeline. The reagent booster is connected with a detection reagent tube, and the other end of the detection reagent tube is connected with the probe tube; one end of the micro-permeation tube is used for being embedded in a human blood vessel an