Abstract: The real-time online monitoring system for γ-ray absorbed dose rate was established to study the relationship between the photocurrent of semi-conductive silicon photo-cell BBZSGD-4 and γ-ray absorbed dose rate under the open circuit. The radioactive experiments in ⁶⁰Co γ radiation field show that photo-cell BBZSGD-4 has good response to ⁶⁰Co γ-ray, and their relationship accords with the linear law. The photocurrent of photo-cell can be up to 1.26 μA when the absorbed dose rate is 94.54 Gy/min. The relationship between photocurrent and the absorbed dose accords with exponential law when absorbed dose rate is 50 Gy/min, and the attenuation of photocurrent is 1% when the absorbed dose is 5 445.8 Gy. Thus photo-cell BBZSGD-4 has the potential to be a real-time detector to detect low absorbed dose rate in ⁶⁰Co γ radiation field.