The invention discloses an implantable human blood glucose concentration continuous monitoring system based on optical fiber attenuation total reflection, consisting of double optical paths and comprising a light source, an attenuator, a spectroscope, an optical fiber coupling device, an optical fiber ATR sensor, a measurement photodetector, a reference photodetector, a data collection system anda computer, wherein after being attenuated by the attenuator, the light source is divided into two optical paths formed by a measurement light and a reference light; in one optical path, the measurement light enters the optical fiber ATR sensor in a coupling way through a coupling method by the optical fiber coupling device and is received by the measurement photodetector via a transmission lightof the optical fiber ATR sensor; in the other optical path, the reference light is directly received by the reference photodetector; signals recevied by the measurement photodetector and the reference photodetector are synchronously collected by the data collection system, are sent to the computer and are in analysis treatment, and the computer displays a measurement result and is also connected with the light source. The invention adopts a direct measurement in vivo method to directly measure the glucose concentration in a tissue fluid, thereby avoiding an error of measurement in vitro.